Display device with touch detecting function and electronic apparatus

ABSTRACT

A display device with a touch detecting function includes wiring for touch arranged in a peripheral area positioned on the outside of a display area, and a selection switch that selects one of drive electrodes to be coupled to the wiring for touch. A drive electrode scanning unit selects one of drive electrodes and includes a plurality of transfer circuits in the peripheral area. Part of the transfer circuits is a transfer circuit that performs output to the selection switch.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a continuation application of U.S.application Ser. No. 14/546,546, filed on Nov. 18, 2014, whichapplication claims priority to Japanese Priority Patent Application JP2013-242390 filed in the Japan Patent Office on Nov. 22, 2013, theentire content of which is hereby incorporated by reference.

BACKGROUND

1. Technical Field

The present invention relates to a display device capable of detectingan external contiguous object and to an electronic apparatus, and inparticular to a display device with a touch detecting function capableof detecting an external contiguous object approaching the device fromthe outside based on a change in capacitance and to an electronicapparatus.

2. Description of the Related Art

Touch detection devices capable of detecting an external contiguousobject, which are what is called touch panels, have been attractingattention in recent years. Touch panels are attached or integrated ondisplay devices, such as liquid-crystal display devices, and are usedfor display devices with a touch detecting function. Display deviceswith a touch detecting function cause a display device to displayvarious types of button images and the like. This enables input ofinformation using the touch panel as a substitute for general mechanicalbuttons. Such display devices with a touch detecting function includinga touch panel require no input device, such as a keyboard, a mouse, anda keypad. As a result, display devices with a touch detecting functionhave been increasingly used for portable information terminals, such asmobile phones, besides for computers.

Some types of technologies for touch detection devices are known,including optical, resistive, and capacitive technologies, for example.By applying a capacitive touch detection device to a portableinformation terminal, it is possible to provide an apparatus having arelatively simple structure and requiring less power consumption. Forexample, Japanese Patent Application Laid-open Publication No.2012-221485 (JP-A-2012-221485) discloses a capacitive touch panel.

In a display device with a touch detecting function, a display functionand a touch detecting function are integrated with each other, so thatan operation for touch detection may affect a display, for example. Incontrast, with the display device with a touch detecting functiondisclosed in JP-A-2012-221485, influence on the display can be reducedeven when a touch is detected. The display device with a touch detectingfunction disclosed in JP-A-2012-221485 includes a drive unit thatselectively applies a direct current (DC) drive voltage VcomDC or analternative current (AC) drive signal VcomAC to a drive electrode. Inthe display device with a touch detecting function, a display element isdriven for display, a drive signal is applied to the drive electrode,and a signal corresponding to the drive signal is output from a touchdetection electrode. Accordingly, two pieces of wiring for supplying theDC drive voltage VcomDC and the AC drive signal VcomAC to the driveelectrode need to be routed in a picture frame area.

In the display device with a touch detecting function disclosed inJP-A-2012-221485, a resistance of the wiring that supplies the drivesignal may affect a time constant of a waveform of the drive signal, andmay affect accuracy in touch detection. Due to this, to reduce aconnection resistance, a width of the wiring needs to be increased.However, when the width of the wiring is increased, the picture framearea that does not contribute to a display area may be enlarged.

The present invention is made in view of such a situation, and providesa display device with a touch detecting function and an electronicapparatus that can enhance the accuracy in touch detection or narrow thepicture frame area.

SUMMARY

According to an aspect, a display device with a touch detecting functionincludes: a plurality of pixel electrodes arranged in a display area; aplurality of drive electrodes arranged opposed to the pixel electrodes;a control device that applies a drive voltage for display between theplurality of pixel electrodes and the plurality of drive electrodes; atouch detection electrode opposed to the plurality of drive electrodes;wiring for touch that is arranged in a peripheral area positionedoutside of the display area and supplies a drive signal for touch to theplurality of drive electrodes; and a selection switch that selects oneof the plurality of drive electrodes to be coupled to the wiring fortouch. The control device includes a drive electrode scanning unitselecting one of the plurality of drive electrodes, the drive electrodescanning unit includes a plurality of transfer circuits for supplyingthe drive signal for touch in the peripheral area, and part of thetransfer circuits is a transfer circuit that controls the selectionswitch.

According to another aspect, an electronic apparatus includes: a displaydevice with a touch detecting function, the display device with a touchdetecting function including: a plurality of pixel electrodes arrangedin a display area; a plurality of drive electrodes arranged opposed tothe pixel electrodes; a control device that applies a drive voltage fordisplay between the plurality of pixel electrodes and the plurality ofdrive electrodes based on an image signal; a touch detection electrodeopposed to the drive electrode; a touch detection unit coupled to thetouch detection electrode; wiring for touch that is arranged in apicture frame area positioned outside of the display area and supplies adrive signal for touch to the plurality of drive electrodes; and aselection switch that selects one of the plurality of drive electrodesto be coupled to the wiring for touch. The control device includes adrive electrode scanning unit that selects one of the plurality of driveelectrodes to which the drive signal for touch is supplied , the driveelectrode scanning unit includes a plurality of transfer circuits forsupplying the drive signal for touch to the one of the plurality ofdrive electrodes, and part of the transfer circuits is a transfercircuit that controls the selection switch.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram of an exemplary configuration of a displaydevice with a touch detecting function according to a first embodiment;

FIG. 2 is an explanatory view illustrating a state where no finger is incontact or in contiguity with the device for explanation of the basicprinciple of a capacitive touch detection technology;

FIG. 3 is a view for explaining an example of an equivalent circuit inthe state where no finger is in contact or in contiguity with the deviceillustrated in FIG. 2;

FIG. 4 is an explanatory view illustrating a state where a finger is incontact or in contiguity with the device for explanation of the basicprinciple of the capacitive touch detection technology;

FIG. 5 is a view for explaining an example of an equivalent circuit inthe state where the finger is in contact or in contiguity with thedevice illustrated in FIG. 4;

FIG. 6 is a diagram of an example of a waveform of a drive signal and atouch detection signal;

FIG. 7 is a view of an example of a module on which the display devicewith a touch detecting function according to the first embodiment ismounted;

FIG. 8 is a sectional view of a schematic sectional structure of adisplay unit with a touch detecting function according to the firstembodiment;

FIG. 9 is a diagram illustrating an example of a control device of thedisplay device with a touch detecting function according to the firstembodiment;

FIG. 10 is a circuit diagram of pixel arrangement of the display unitwith a touch detecting function according to the first embodiment;

FIG. 11 is a schematic diagram for explaining a relation between asource driver and a pixel signal line in the module on which the displaydevice with a touch detecting function according to the first embodimentis mounted;

FIG. 12 is a perspective view of an exemplary configuration of driveelectrodes and touch detection electrodes of the display unit with atouch detecting function according to the first embodiment;

FIG. 13 is a schematic diagram representing an operation example oftouch detection in the display device with a touch detecting functionaccording to the first embodiment;

FIG. 14 is a schematic diagram representing an operation example oftouch detection in the display device with a touch detecting functionaccording to the first embodiment;

FIG. 15 is a schematic diagram representing an operation example oftouch detection in the display device with a touch detecting functionaccording to the first embodiment;

FIG. 16 is a block diagram illustrating a drive signal generation unitof a drive electrode driver according to the first embodiment;

FIG. 17 is a block diagram illustrating the drive electrode driveraccording to the first embodiment;

FIG. 18 is a block diagram illustrating a drive unit of the driveelectrode driver according to the first embodiment;

FIG. 19 is a block diagram illustrating a drive electrode driveraccording to a comparative example;

FIG. 20 is an explanatory diagram schematically illustrating a width ofwiring for touch in a picture frame (peripheral) according to thecomparative example;

FIG. 21 is an explanatory diagram schematically illustrating a width ofa wiring for touch in a picture frame according to the first embodiment;

FIG. 22 is an explanatory diagram illustrating an example of a timingwaveform of the display device with a touch detecting function accordingto the first embodiment;

FIG. 23 is an explanatory diagram illustrating a modification of thetiming waveform of the display device with a touch detecting function;

FIG. 24 is a block diagram illustrating a drive electrode driveraccording to a second embodiment;

FIG. 25 is an explanatory diagram illustrating an example of a timingwaveform of a display device with a touch detecting function accordingto the second embodiment;

FIG. 26 is a block diagram illustrating the drive electrode driveraccording to a modification of the second embodiment;

FIG. 27 is an explanatory diagram illustrating an example of a timingwaveform of the display device with a touch detecting function accordingto the modification of the second embodiment;

FIG. 28 is a block diagram illustrating a drive electrode driveraccording to a third embodiment;

FIG. 29 is a block diagram illustrating a drive signal generation unitof the drive electrode driver according to the third embodiment;

FIG. 30 is an explanatory diagram illustrating an example of a timingwaveform of a display device with a touch detecting function accordingto the third embodiment;

FIG. 31 is a block diagram illustrating a drive signal generation unitof a drive electrode driver according to a fourth embodiment;

FIG. 32 is a block diagram illustrating the drive electrode driveraccording to the fourth embodiment;

FIG. 33 is an explanatory diagram illustrating an example of a timingwaveform of a display device with a touch detecting function accordingto the fourth embodiment;

FIG. 34 is a block diagram illustrating a drive electrode driveraccording to a fifth embodiment;

FIG. 35 is an explanatory diagram illustrating an example of a timingwaveform of a display device with a touch detecting function accordingto the fifth embodiment;

FIG. 36 is a cross-sectional view representing a schematiccross-sectional structure of a display unit with a touch detectingfunction according to a modification;

FIG. 37 is a schematic of an example of an electronic apparatus to whichthe display device with a touch detecting function according to thepresent embodiments is applied;

FIG. 38 is a schematic of an example of an electronic apparatus to whichthe display device with a touch detecting function according to thepresent embodiments is applied;

FIG. 39 is a schematic of an example of an electronic apparatus to whichthe display device with a touch detecting function according to thepresent embodiments is applied;

FIG. 40 is a schematic of an example of an electronic apparatus to whichthe display device with a touch detecting function according to thepresent embodiments is applied;

FIG. 41 is a schematic of an example of an electronic apparatus to whichthe display device with a touch detecting function according to thepresent embodiments is applied;

FIG. 42 is a schematic of an example of an electronic apparatus to whichthe display device with a touch detecting function according to thepresent embodiments is applied;

FIG. 43 is another schematic of the example of the electronic apparatusto which the display device with a touch detecting function according tothe present embodiments is applied; and

FIG. 44 is still a schematic of an example of an electronic apparatus towhich the display device with a touch detecting function according tothe present embodiments is applied.

DETAILED DESCRIPTION

Exemplary aspects (embodiments) according to the present invention aredescribed in greater detail with reference to the accompanying drawings.The contents disclosed in the following embodiments are not intended tolimit the present invention. Components described below includecomponents easily conceivable by those skilled in the art and componentssubstantially identical. The components described below can be combinedas appropriate. The disclosure is merely an example, and the presentinvention naturally encompasses appropriate modifications that can beeasily conceivable by those skilled in the art without departing fromthe gist of the invention. For clarity of description, a width, athickness, a shape, and the like of each component may be schematicallyrepresented in the drawings as compared to an actual aspect. However, itis merely an example and the present invention is not limited thereto.The elements in the specification and the other drawings that are thesame as those described in drawings that have been already described maybe denoted by the same reference numerals, and redundant descriptionwill not be repeated in some cases.

First Embodiment

FIG. 1 is a block diagram of an exemplary configuration of a displaydevice with a touch detecting function according to a first embodiment.A display device 1 with a touch detecting function includes a displayunit 10 with a touch detecting function, a control unit 11, a gatedriver 12, a source driver 13, a source selector unit 13S, a driveelectrode driver 14, and a touch detection unit 40. In the displaydevice 1 with a touch detecting function, the display unit 10 with atouch detecting function has a touch detecting function. The displayunit 10 with a touch detecting function is a device in which aliquid-crystal display unit 20 provided with liquid-crystal displayelements as display elements is integrated with a capacitive touchdetecting unit 30.

The present embodiment discloses a liquid crystal display device (liquidcrystal display unit 20) as an example of a display function layerhaving an image display function for displaying an image in a displayarea. Examples of other applications include, but are not limited to,various flat-panel type display devices such as organicelectroluminescent (EL) devices, other self-luminous display devices, orelectronic paper display devices having an electrophoresis element andthe like. It is needless to say that the size of the device is notspecifically limited, and a middle-size, a small size, and a large sizecan be used.

The liquid-crystal display unit 20 performs sequential scanning on eachhorizontal line based on a scanning signal Vscan supplied from the gatedriver 12, thereby performing display, which will be described later.The control unit 11 is a circuit that supplies control signals to thegate driver 12, the source driver 13, the drive electrode driver 14, andthe touch detecting unit 40 based on a video signal Vdisp supplied fromthe outside, thereby controlling these units so as to operate insynchronization with one another. A control device in the presentembodiment includes the control unit 11, the gate driver 12, the sourcedriver 13, and the drive electrode driver 14.

The gate driver 12 has a function to sequentially select a horizontalline to be a target of display drive of the display unit 10 with a touchdetecting function based on the control signal supplied from the controlunit 11.

The source driver 13 is a circuit for supplying a pixel signal Vpix toeach pixel Pix (sub-pixel SPix) (described later) of the display unit 10with a touch detecting function based on the control signal suppliedfrom the control unit 11. As described later, the source driver 13generates a pixel signal obtained by time-division multiplexing pixelsignals Vpix of a plurality of sub-pixels SPix of the liquid crystaldisplay unit 20 from a video signal Vdisp for one horizontal line, andsupplies the generated pixel signal to the source selector unit 13S. Thesource driver 13 also generates a switch control signal Vsel requiredfor separating the pixel signal Vpix multiplexed with an image signalVsig, and supplies the switch control signal Vsel to the source selectorunit 13S together with the pixel signal Vpix. The source selector unit13S can reduce the number of pieces of wiring between the source driver13 and the control unit 11.

The drive electrode driver 14 is a circuit for supplying a drive signalfor touch detection (touch drive signal, hereinafter referred to as adrive signal) VcomAC and a drive voltage for display VcomDC as a voltagefor display to a drive electrode COML (described later) of the displayunit 10 with a touch detecting function based on the control signalsupplied from the control unit 11.

The touch detecting unit 40 is a circuit that detects whether a touch(the contact state described above) is made on the touch detecting unit30 based on the control signal supplied from the control unit 11 and atouch detection signal Vdet supplied from the touch detecting unit 30 ofthe display unit 10 with a touch detecting function. If a touch is made,the touch detecting unit 40 derives the coordinates of the touch in atouch detection area. The touch detecting unit 40 includes a touchdetection signal amplifier 42, an analog/digital (A/D) converter 43, asignal processing unit 44, a coordinate extracting unit 45, and adetection timing control unit 46.

The touch detection signal amplifier 42 amplifies a touch detectionsignal Vdet supplied from the touch detecting unit 30. The touchdetection signal amplifier 42 may include an analog low pass filter. Theanalog low pass filter removes high-frequency components (noisecomponents) included in the touch detection signal Vdet, therebyextracting and outputting touch components.

Basic Principle of Capacitive Touch Detection

The touch detecting unit 30 operates based on the basic principle ofcapacitive touch detection, thereby outputting the touch detectionsignal Vdet. The following describes the basic principle of touchdetection in the display device 1 with a touch detecting functionaccording to the present embodiment with reference to FIG. 1 to FIG. 6.FIG. 2 is an explanatory view illustrating a state where no finger is incontact or in contiguity with the device for explanation of the basicprinciple of a capacitive touch detection technology. FIG. 3 is a viewfor explaining an example of an equivalent circuit in the state where nofinger is in contact or in contiguity with the device illustrated inFIG. 2. FIG. 4 is an explanatory view illustrating a state where afinger is in contact or in contiguity with the device for explanation ofthe basic principle of the capacitive touch detection technology. FIG. 5is a view for explaining an example of an equivalent circuit in thestate where the finger is in contact or in contiguity with the deviceillustrated in FIG. 4. FIG. 6 is a diagram of an example of a waveformof a drive signal and a touch detection signal.

As illustrated in FIG. 2, capacitive elements C1 include a pair ofelectrodes of a drive electrode E1 and a touch detection electrode E2arranged in a manner facing each other with a dielectric D interposedtherebetween, for example. As illustrated in FIG. 3, a first end of thecapacitive element C1 is coupled to an alternating-current (AC) signalsource (a drive signal source) S, whereas a second end is coupled to avoltage detector (a touch detecting unit) DET. The voltage detector DETis an integration circuit included in the touch detection signalamplifier 42 illustrated in FIG. 1, for example.

If the AC signal source S applies an alternating-current (AC)rectangular wave Sg at a predetermined frequency (e.g., approximatelyseveral kilohertz to several hundred kilohertz) to the drive electrodeE1 (first end of the capacitive element C1), an output waveform (touchdetection signal Vdet) is generated via the voltage detector DET coupledto the touch detection electrode E2 (second end of the capacitiveelement C1). The AC rectangular wave Sg corresponds to a drive signalVcomAC, which will be described later.

In the state where no finger is in contact (or in contiguity) with thedevice (a non-contact state), an electric current I₀ depending on thecapacitance value of the capacitive element C1 flows in association withcharge and discharge to the capacitive element C1 as illustrated in FIG.2 and FIG. 3. As illustrated in FIG. 6, the voltage detector DETconverts fluctuations in the electric current I₀ depending on the ACrectangular wave Sg into fluctuations in the voltage (a waveform V₀indicated by a solid line).

By contrast, in the state where a finger is in contact (or incontiguity) with the device (a contact state), capacitance C2 generatedby the finger is in contact or in contiguity with the touch detectionelectrode E2 as illustrated in FIG. 4. This blocks capacitance of afringe between the drive electrode E1 and the touch detection electrodeE2. As a result, the capacitive element C1′ having a capacitance valuesmaller than that of the capacitive element C1 is obtained. In theequivalent circuit illustrated in FIG. 5, an electric current I_(i)flows through the capacitive element C1′. As illustrated in FIG. 6, thevoltage detector DET converts fluctuations in the electric current I₁depending on the AC rectangular wave Sg into fluctuations in the voltage(a waveform V₁ indicated by a dotted line). In this case, the waveformV₁ has amplitude smaller than that of the waveform V₀. Thus, an absolutevalue |ΔV| of the voltage difference between the waveform V₀ and thewaveform V₁ varies depending on an influence of an object, such as afinger, approaching the device from the outside. To detect the absolutevalue |ΔV| of the voltage difference between the waveform V₀ and thewaveform V₁ with high accuracy, the voltage detector DET preferablyoperates while providing a period Reset for resetting charge anddischarge of a condenser based on the frequency of the AC rectangularwave Sg by performing switching in the circuit.

The touch detecting unit 30 illustrated in FIG. 1 performs sequentialscanning on each detection block based on the drive signal Vcom (drivesignal VcomAC, which will be described later) supplied from the driveelectrode driver 14, thereby performing touch detection.

The touch detecting unit 30 outputs the touch detection signal Vdet foreach detection block from a plurality of touch detection electrodes TDL,which will be described later, via the voltage detector DET illustratedin FIG. 3 or FIG. 5, thereby supplying the touch detection signal Vdetto the A/D converter 43 of the touch detecting unit 40.

The A/D converter 43 is a circuit that samples an analog signal outputfrom the touch detection signal amplifier 42 at a timing synchronizedwith the drive signal VcomAC, thereby converting the analog signal intoa digital signal.

The signal processing unit 44 includes a digital filter. The digitalfilter reduces frequency components (noise components) other than thefrequency at which the drive signal Vcom is sampled in the output signalof the A/D converter 43. The signal processing unit 44 is a logiccircuit that detects whether a touch is made on the touch detecting unit30 based on the output signal from the A/D converter 43. The signalprocessing unit 44 performs processing for extracting only the voltagedifference caused by the finger. The voltage difference caused by thefinger corresponds to the absolute value |ΔV| of the difference betweenthe waveform V₀ and the waveform V₁. The signal processing unit 44 mayperform an arithmetic operation for averaging the absolute value |ΔV|per detection block, thereby deriving the average value of the absolutevalue |ΔV|. Thus, the signal processing unit 44 can reduce an influencecaused by noise. The signal processing unit 44 compares the detectedvoltage difference caused by the finger with a predetermined thresholdvoltage. If the detected voltage difference is equal to or larger thanthe threshold voltage, the signal processing unit 44 determines that anexternal contiguous object approaching the device from the outside is incontact with the device. If the detected voltage difference is smallerthan the threshold voltage, the signal processing unit 44 determinesthat the external contiguous object is not in contact with the device.Thus, the touch detecting unit 40 can perform touch detection.

The coordinate extracting unit 45 is a logic circuit that derives, whena touch is detected by the signal processing unit 44, the touch panelcoordinates of the touch. The detection timing control unit 46 performscontrol such that the A/D converter 43, the signal processing unit 44,and the coordinate extracting unit 45 operate in synchronization withone another. The coordinate extracting unit 45 outputs touch panelcoordinates as a signal output Vout.

Module

FIG. 7 is a view of an example of a module on which the display devicewith a touch detecting function according to the first embodiment ismounted. As illustrated in FIG. 7, the display device 1 with a touchdetecting function includes a pixel substrate 2 (TFT substrate 21) and aflexible printed board T (described later). A chip on glass (COG) 19 ismounted on the pixel substrate 2 (TFT substrate 21), and a display areaAd and a picture frame (peripheral) area Gd of the liquid crystaldisplay unit 20 described above are formed thereon. The COG 19 is a chipof an IC driver mounted on the TFT substrate 21 and is a control deviceincluding circuits required for a display operation, such as the controlunit 11 and the source driver 13 illustrated in FIG. 1. In the presentembodiment, the source driver 13 and the source selector unit 13Sdescribed above are formed on the TFT substrate 21. The source driver 13and the source selector unit 13S may be incorporated in the COG 19.Drive electrode scanning units 14A and 14B as part of the driveelectrode driver 14 are formed on the TFT substrate 21. The gate driver12 is formed as gate drivers 12A and 12B on the TFT substrate 21. Thedisplay device 1 with a touch detecting function may incorporatecircuits such as the drive electrode scanning units 14A and 14B and thegate driver 12 in the COG 19.

FIG. 1 schematically illustrates the drive electrode block B of thedrive electrode COML and the touch detection electrode TDL in thedisplay unit 10 with a touch detecting function viewed in a directionperpendicular to the surface of the TFT substrate 21. The touchdetection electrode TDL is formed to intersect with the drive electrodeblock B (drive electrode COML) in a grade separated manner. The displayunit 10 with a touch detecting function includes, in a directionperpendicular to the surface of the TFT substrate 21, the driveelectrode COML and a scanning line GCL (described later) that is formedto extend in a direction parallel to the drive electrode COML withoutintersecting therewith.

The drive electrode COML is divided into a plurality of stripe electrodepatterns extending in one direction. When a touch detection operation isperformed, the drive electrode driver 14 sequentially supplies the drivesignal VcomAC to each of the electrode patterns. The stripe electrodepatterns of the drive electrode COML to which the drive signals VcomACare supplied at the same time are the drive electrode blocks Billustrated in FIG. 7. The drive electrode block B (drive electrodeCOML) is formed in a direction along one side of the display unit 10with a touch detecting function, and the touch detection electrode TDL(described later) is formed in a direction along the other side of thedisplay unit 10 with a touch detecting function. An output of the touchdetection electrode TDL is arranged on a short-side side of the displayunit 10 with a touch detecting function, and is coupled to the touchdetection unit 40 mounted on the flexible printed board T via theflexible printed board T. In this way, the touch detection unit 40 ismounted on the flexible printed board T and coupled to each of the touchdetection electrodes TDL that are arranged in parallel. The flexibleprinted board T may be any terminal and is not limited to the flexibleprinted board. In this case, the touch detection unit 40 is provided tothe outside of the module.

Among the control unit 11, the source driver 13, and the drive electrodedriver 14, a drive signal generation unit (described later) is mountedas the COG 19 on the pixel substrate 2. The source selector unit 13S isformed in the vicinity of the display area Ad on the TFT substrate 21using a TFT element. In the display area Ad, a large number of pixelsPix (described later) are arranged in a matrix. The picture frame areasGd and Gd are areas in which no pixel Pix is arranged viewed in adirection perpendicular to the surface of the TFT substrate 21. The gatedriver 12 and the drive electrode scanning units 14A and 14B in thedrive electrode driver 14 are arranged in the picture frame areas Gd andGd.

The gate driver 12 includes the gate drivers 12A and 12B, and is formedon the TFT substrate 21 using TFT elements. The gate drivers 12A and 12Bcan drive the display area Ad from both sides across the display area Adin which the sub-pixels SPix (pixels) (described later) are arranged ina matrix. In the following description, the gate driver 12A is referredto as a first gate driver 12A and the gate driver 12B is referred to asa second gate driver 12B. The scanning line GCL (described later) isarranged between the first gate driver 12A and the second gate driver12B. The scanning line GCL (described later) is arranged so as to extendin a direction parallel to the extending direction of the driveelectrode COML viewed in the direction perpendicular to the surface ofthe TFT substrate 21.

The drive electrode scanning units 14A and 14B are formed on the TFTsubstrate 21 using TFT elements. The drive electrode scanning units 14Aand 14B receive the drive voltage for display VcomDC from the drivesignal generation unit via wiring for display LDC, and receive the drivesignal VcomAC via wiring for touch LAC. The drive electrode scanningunits 14A and 14B occupy a certain width Gdv in the picture frame areaGd. The drive electrode scanning units 14A and 14B can drive each of thedrive electrode blocks B arranged in parallel from both sides. Thewiring for display LDC for supplying the drive voltage for displayVcomDC and the wiring for touch LAC for supplying the drive signal fortouch VcomAC are arranged in parallel in the picture frame areas Gd andGd. The wiring for display LDC is arranged closer to the display area Adside than the wiring for touch LAC. With this configuration, the drivevoltage for display VcomDC supplied from the wiring for display LDCstabilizes a potential state at the end of the display area Ad.Accordingly, display is stabilized especially in a liquid crystaldisplay unit using liquid crystals of a lateral electric-field mode.

The display device 1 with a touch detecting function illustrated in FIG.7 outputs the touch detection signal Vdet described above from one sideof the display unit 10 with a touch detecting function. Due to this, inthe display device 1 with a touch detecting function, wiring can beeasily routed in coupling to the touch detection unit 40 via theflexible printed board T as a terminal part.

Display Unit with a Touch Detecting Function

The following describes an exemplary configuration of the display unit10 with a touch detecting function in greater detail. FIG. 8 is asectional view of a schematic sectional structure of the display unitwith a touch detecting function according to the first embodiment. FIG.9 is a diagram illustrating an example of the control device of thedisplay device with a touch detecting function according to the firstembodiment. FIG. 10 is a circuit diagram representing a pixel array ofthe display unit with a touch detecting function according to the firstembodiment.

As illustrated in FIG. 8, the display unit 10 with a touch detectingfunction includes a pixel substrate 2, a counter substrate 3, and aliquid-crystal layer 6. The counter substrate 3 is arranged in a mannerfacing the surface of the pixel substrate 2 in a perpendiculardirection. The liquid-crystal layer 6 is inserted between the pixelsubstrate 2 and the counter substrate 3.

The liquid-crystal layer 6 modulates light passing therethroughdepending on the state of an electric field. For example, theliquid-crystal layer 6 is a liquid-crystal display unit using liquidcrystals of a lateral electric-field mode, such as a fringe fieldswitching (FFS) mode or an in-plane switching (IPS) mode. An orientationfilm may be provided between the liquid-crystal layer 6 and the pixelsubstrate 2 and between the liquid-crystal layer 6 and the countersubstrate 3 illustrated in FIG. 8.

The counter substrate 3 includes a glass substrate 31 and a color filter32 formed on one surface of the glass substrate 31. The touch detectionelectrode TDL serving as the detection electrode of the touch detectingunit 30 is formed on the other surface of the glass substrate 31. Apolarization plate 35 is provided on the touch detection electrode TDL.

The pixel substrate 2 includes the TFT substrate 21, a plurality ofpixel electrodes 22, a plurality of drive electrodes COML, and aninsulation layer 24. The TFT substrate 21 serves as a circuit board. Thepixel electrodes 22 are arranged in a matrix on the TFT substrate 21.The drive electrodes COML are formed between the TFT substrate 21 andthe pixel electrodes 22. The insulation layer 24 electrically insulatesthe pixel electrodes 22 from the drive electrodes COML.

System Configuration Example of Display Device

The pixel substrate 2 includes the display area Ad, the COG 19 servingas an interface (I/F) and a timing generator, the first gate driver 12A,the second gate driver 12B, and the source driver 13 on the TFTsubstrate 21. The flexible printed board T illustrated in FIG. 7transmits an external signal to the COG 19 illustrated in FIG. 9 that isarranged as the COG 19 illustrated in FIG. 7, or driving power fordriving the COG 19. The pixel substrate 2 is provided on the surface ofthe TFT substrate 21 as a transparent insulating substrate (for example,a glass substrate). The pixel substrate 2 includes the display area Adin which a large number of pixels including liquid crystal cells arearranged in a matrix, the source driver (horizontal drive circuit) 13,and the gate drivers (vertical drive circuits) 12A and 12B. The gatedrivers (vertical drive circuits) 12A and 12B are arranged at both sidesof the display area Ad as the first gate driver 12A and the second gatedriver 12B.

The display area Ad has a matrix structure in which the sub-pixels SPixincluding the liquid crystal layer 6 are arranged in m rows by ncolumns. In the specification, the row means a pixel row including msub-pixels SPix arrayed in one direction. The column means a pixelcolumn including n sub-pixels SPix arrayed in a direction orthogonal tothe direction in which the row is arrayed. Values of m and n aredetermined corresponding to display resolution in a vertical directionand display resolution in a horizontal direction. In the display areaAd, with respect to the m rows by n columns of pixels Vpix, the scanninglines GCL_(m+1), GCL_(m+2), GCL_(m+3). . . are wired for each row, andsignal lines SGL_(n+1), SGL₊₂, SGL_(n+3), SGL_(n+4), SGL_(n+5). . . arewired for each column. In the following embodiments, the scanning linesGCL_(m+1), GCL_(m+2), GCL_(m+3). . . may be represented as the scanningline GCL, and the signal lines SGL_(n+1), SGL_(n+2), SGL_(n+3),SGL_(n+4), SGL_(n+5). . . may be represented as the signal line SGL, insome cases.

A master clock, a horizontal synchronizing signal, and a verticalsynchronizing signal as external signals are input to the pixelsubstrate 2 from the outside and are supplied to the COG 19. The COG 19converts (boosts) level of the master clock, the horizontalsynchronizing signal, and the vertical synchronizing signal with voltageamplitude of an external power supply into voltage amplitude of aninternal power supply required for driving the liquid crystal. The COG19 causes the master clock, the horizontal synchronizing signal, and thevertical synchronizing signal to pass through the timing generator, andgenerates a vertical start pulse VST, a vertical clock pulse VCK, ahorizontal start pulse HST, and a horizontal clock pulse HCK. The COG 19supplies the vertical start pulse VST and the vertical clock pulse VCKto the first gate driver 12A and the second gate driver 12B, andsupplies the horizontal start pulse HST and the horizontal clock pulseHCK to the source driver 13. The COG 19 generates the drive voltage fordisplay (counter electrode electric potential) VCOM that is given toeach of the pixels in common with respect to the pixel electrode foreach sub-pixel SPix and is called a common potential, and gives thedrive voltage for display VCOM to the drive electrode COML.

The first gate driver 12A and the second gate driver 12B may include ashift register described later, and may further include a latch circuitand the like. When the vertical start pulse VST is supplied to the firstgate driver 12A and the second gate driver 12B, the latch circuitsequentially samples and latches display data output from the COG 19 insynchronization with the vertical clock pulse VCK in one horizontalperiod. The first gate driver 12A and the second gate driver 12Bsequentially output the digital data of one line latched by the latchcircuit as a vertical scanning pulse to be supplied to the scanning lineGCL so as to sequentially select the sub-pixels SPix row by row. Thefirst gate driver 12A and the second gate driver 12B are arranged in theextending direction of the scanning line GCL so as to hold the scanningline GCL therebetween. The first gate driver 12A and the second gatedriver 12B sequentially output the data from an upper side of thedisplay area Ad, which is an upper direction of vertical scanning, to alower side of the display area Ad, which is a lower direction ofvertical scanning.

For example, 6-bit digital image signals Vsig of R (red), G (green), andB (blue) are supplied to the source driver 13. The source driver 13writes display data, via the signal line SGL, into each of thesub-pixels SPix in a row selected by vertical scanning with the firstgate driver 12A and the second gate driver 12B for each pixel, for aplurality of pixels, or for all of the pixels.

The TFT substrate 21 includes a thin-film transistor (TFT) element Tr ofeach sub-pixel SPix illustrated in FIG. 9 and FIG. 10 and wiring, suchas a pixel signal line SGL and a scanning line GCL. The pixel signalline SGL supplies the pixel signal Vpix to each pixel electrode 22illustrated in FIG. 8, whereas the scanning line GCL drives each TFTelement Tr. Thus, the pixel signal line SGL extends on a plane parallelto the surface of the TFT substrate 21 and supplies the pixel signalVpix used to display an image to a pixel. The liquid-crystal displayunit 20 illustrated in FIG. 10 includes a plurality of sub-pixels SPixarranged in a matrix. The sub-pixel SPix includes a TFT element Tr and aliquid crystal element LC. The TFT element Tr is formed of a thin-filmtransistor, and specifically of an n-channel metal oxide semiconductor(MOS) TFT in this example. The source of the TFT element Tr is coupledto the pixel signal line SGL, the gate thereof is coupled to thescanning line GCL, and the drain thereof is coupled to a first end ofthe liquid-crystal element LC. The first end of the liquid-crystalelement LC is coupled to the drain of the TFT element Tr, whereas asecond end thereof is coupled to the drive electrode COML.

The first gate driver 12A and the second gate driver 12B illustrated inFIG. 9 applies the vertical scanning pulse to a gate of the TFT elementTr of the sub-pixel SPix via the scanning line GCL illustrated in FIG.10 so as to sequentially select one row (one horizontal line) of thesub-pixels SPix formed in a matrix in the display area Ad as a displaydriving target. The source driver 13 supplies, via the SGL, the pixelsignal Vpix to each of the sub-pixels SPix including one horizontal linethat is sequentially selected by the first gate driver 12A and thesecond gate driver 12B. In these sub-pixels SPix, display for onehorizontal line is performed corresponding to the supplied pixel signalVpix. The drive electrode driver 14 applies the drive signal for display(drive voltage for display VcomDC) to drive the drive electrode COML.

As described above, in the display device 1 with a touch detectingfunction, one horizontal line is sequentially selected when the firstgate driver 12A and the second gate driver 12B are driven tosequentially scan the scanning lines GCL_(m+1), GCL_(m−2), andGCL_(m+3). In the display device 1 with a touch detecting function, thesource driver 13 supplies the pixel signal to the pixel Vpix belongingto one horizontal line, so that display is performed for each horizontalline. When performing the display operation, the drive electrode driver14 applies the drive signal Vcom to the drive electrode COMLcorresponding to the horizontal line.

In the color filter 32 illustrated in FIG. 8, color areas of the colorfilter colored in three colors of red (R), green (G), and blue (B) areperiodically arranged, for example. Three color areas 32R, 32G, and 32Bof R, G, and B (refer to FIG. 10) are associated, as a set of pixel Pix,with each of the sub-pixels SPix illustrated in FIG. 10 described above.The color filter 32 is opposed to the liquid crystal layer 6 in adirection perpendicular to the TFT substrate 21. The colors of the colorfilter 32 may be any other combination so long as they are colored indifferent colors.

The sub-pixel SPix illustrated in FIG. 10 is coupled to other sub-pixelsSPix belonging to the same row in the liquid-crystal display unit 20 bythe scanning line GCL. The scanning line GCL is coupled to the gatedriver 12 and is supplied with the scanning signal Vscan from the gatedriver 12. The sub-pixel SPix is further coupled to other sub-pixelsSPix belonging to the same column in the liquid-crystal display unit 20by the pixel signal line SGL. The pixel signal line SGL is coupled tothe source driver 13 and is supplied with the pixel signal Vpix from thesource driver 13.

FIG. 11 is a schematic diagram for explaining a relation between thesource driver and the pixel signal line in the module on which thedisplay device with a touch detecting function according to the firstembodiment is mounted. As illustrated in FIG. 11, in the display device1 with a touch detecting function, the pixel signal line SGL is coupledto the source driver 13 incorporated in the COG 19 described above viathe source selector unit 13S. The source selector unit 13S isopened/closed corresponding to the switch control signal Vsel.

As illustrated in FIG. 11, the source driver 13 generates and outputsthe pixel signal Vpix based on the image signal Vsig and a source drivercontrol signal supplied from the control unit 11. The source driver 13generates a pixel signal obtained by time-division multiplexing thepixel signals Vpix of a plurality of (three, in this example) sub-pixelsSPix of the liquid crystal display unit 20 of the display unit 10 with atouch detecting function from the image signal Vsig for one horizontalline, and supplies the pixel signal to the source selector unit 13S. Thesource driver 13 also generates the switch control signals Vsel (VselR,VselG, VselB) required for separating the pixel signal Vpix multiplexedwith the image signal Vsig, and supplies the switch control signals Vselto the source selector unit 13S together with the image signal Vsig.This multiplexing reduces the number of pieces of wiring between thesource driver 13 and the source selector unit 13S.

The source selector unit 13S separates the pixel signal Vpix that istime-division multiplexed with the image signal Vsig based on the imagesignal Vsig and the switch control signal Vsel supplied from the sourcedriver 13, and supplies the pixel signal Vpix to the liquid crystaldisplay unit 20 of the display unit 10 with a touch detecting function.

The source selector unit 13S includes, for example, three switches SWR,SWG, and SWB. First ends of the three switches SWR, SWG, and SWB arecoupled to each other and the image signal Vsig is supplied thereto fromthe source driver 13. Each of the second ends of the three switches SWR,SWG, and SWB is coupled to the sub-pixel SPix via the pixel signal lineSGL of the liquid crystal display unit 20 of the display unit 10 with atouch detecting function. Each of the three switches SWR, SWG, and SWBis controlled to be opened or closed with the switch control signalsVsel (VselR, VselG, VselB) supplied from the source driver 13. With thisconfiguration, the source selector unit 13S can sequentially switchesthe switches SWR, SWG, and SWB in a time-division manner to be in an ONstate corresponding to the switch control signal Vsel. The sourceselector unit 13S then separates the pixel signals Vpix (VpixR, VpixG,VpixB) from the multiplexed image signal Vsig. The source selector unit13S supplies the pixel signal Vpix to each of the three sub-pixels SPix.Each of the color areas 32R, 32G, and 32B colored in three colors of red(R), green (G), and blue (B) described above is associated with thesub-pixel SPix. Accordingly, the pixel signal VpixR is supplied to thesub-pixel SPix corresponding to the color area 32R. The pixel signalVpixG is supplied to the sub-pixel SPix corresponding to the color area32G. The pixel signal VpixB is supplied to the sub-pixel SPixcorresponding to the color area 32B.

The sub-pixel SPix is coupled to the other sub-pixels SPix belonging tothe same row in the liquid-crystal display unit 20 by the driveelectrode COML. The drive electrode COML is coupled to the driveelectrode driver 14 and is supplied with the drive voltage for displayVcomDC from the drive electrode driver 14. In other words, a pluralityof sub-pixels SPix belonging to the same row share the drive electrodeCOML in this example.

The gate driver 12 illustrated in FIG. 1 applies the scanning signalVscan to the gate of the TFT element Tr of a sub-pixel SPix via thescanning line GCL illustrated in FIG. 10. Thus, the gate driver 12sequentially selects a row (a horizontal line) out of the sub-pixelsSPix arranged in a matrix in the liquid-crystal display unit 20 as atarget of display drive. The source driver 13 illustrated in FIG. 1supplies the pixel signal Vpix to each of the sub-pixels SPixconstituting the horizontal line sequentially selected by the gatedriver 12 via the pixel signal line SGL illustrated in FIG. 10. Thesesub-pixels SPix perform display of the horizontal line based on thesupplied pixel signal Vpix. The drive electrode driver 14 illustrated inFIG. 1 applies the drive signal Vcom, thereby driving the driveelectrodes COML of each drive electrode block B composed of apredetermined number of drive electrodes COML illustrated in FIG. 7 andFIG. 9.

As described above, the gate driver 12 drives so as to performtime-division sequential scanning on the scanning line GCL, whereby theliquid-crystal display unit 20 sequentially selects a horizontal line.The source driver 13 supplies the pixel signal Vpix to the sub-pixelsSPix belonging to the horizontal line, whereby the liquid-crystaldisplay unit 20 performs display of the horizontal line. To perform thedisplay operation, the drive electrode driver 14 applies the drivevoltage for display VcomDC to a drive electrode block B including thedrive electrodes COML corresponding to the horizontal line.

The drive electrode COML according to the present embodiment functionsas a drive electrode of the liquid-crystal display unit 20 and as adrive electrode of the touch detecting unit 30. FIG. 12 is a perspectiveview of an exemplary configuration of the drive electrodes and the touchdetection electrodes of the display unit with a touch detecting functionaccording to the first embodiment. The drive electrodes COML illustratedin FIG. 12 face the pixel electrodes 22 in the direction perpendicularto the surface of the TFT substrate 21 as illustrated in FIG. 8. Thetouch detecting unit 30 includes the drive electrodes COML provided tothe pixel substrate 2 and the touch detection electrodes TDL provided tothe counter substrate 3. The touch detection electrodes TDL are formedinto stripe electrode patterns extending in a direction intersectingwith the extending direction of the electrode patterns of the driveelectrodes COML. The touch detection electrodes TDL face the driveelectrodes COML in the direction perpendicular to the surface of the TFTsubstrate 21. The electrode patterns of the touch detection electrodesTDL are coupled to the respective inputs of the touch detection signalamplifier 42 of the touch detecting unit 40. The electrode patterns ofthe drive electrodes COML and the touch detection electrodes TDLintersecting with each other generate capacitance at the intersections.The touch detection electrode TDL or the drive electrode COML (driveelectrode block B) are not limited to the shape that is divided into aplurality of stripes. For example, the touch detection electrode TDL orthe drive electrode COML (drive electrode block B) may have a comb-teethshape. Alternatively, the touch detection electrode TDL or the driveelectrode COML (drive electrode block B) may be divided into a pluralityof pieces, and a shape of a slit that divides the drive electrode COMLmay be a straight line or a curved line.

With this configuration, the touch detecting unit 30 performs a touchdetection operation by driving the drive electrode driver 14 so as toperform time-division line-sequential scanning on a drive electrodeblock B illustrated in FIG. 7. Accordingly, the drive electrode block B(one detection block) of the drive electrodes COML is sequentiallyselected in a scanning direction Scan. The touch detecting unit 30 thenoutputs the touch detection signal Vdet from the touch detectionelectrode TDL. Thus, the touch detecting unit 30 performs touchdetection in the detection block.

FIG. 13, FIG. 14, and FIG. 15 are schematic diagrams representing anoperation example of touch detection in the display device with a touchdetecting function according to the first embodiment. FIG. 13, FIG. 14,and FIG. 15 illustrates an applying operation of the drive signal fortouch VcomAC to each of drive electrode blocks B1 to B20 in a case inwhich the drive electrode blocks B of the drive electrode COMLillustrated in FIG. 7 are twenty drive electrode blocks B1 to B20. Adrive signal application block BAC indicates the drive electrode block Bto which the drive signal for touch VcomAC is applied, and other driveelectrode blocks B are in a state in which voltage is not appliedthereto and electric potential is not fixed, that is, a floating state.The drive signal application block BAC indicates the drive electrodeblock B to which the drive signal for touch VcomAC is applied, and otherdrive electrode blocks B may be in a state in which the drive voltagefor display VcomDC is applied thereto and the electric potential isfixed. The drive electrode driver 14 illustrated in FIG. 1 selects thedrive electrode block B3 from among the drive electrode blocks B to betargets of the touch detection operation illustrated in FIG. 13, andapplies the drive signal for touch VcomAC thereto. Next, the driveelectrode driver 14 selects the drive electrode block B4 from among thedrive electrode blocks B illustrated in FIG. 14, and applies the drivesignal for touch VcomAC thereto. Subsequently, the drive electrodedriver 14 selects the drive electrode block B5 from among the driveelectrode blocks B illustrated in FIG. 15, and applies the drive signalfor touch VcomAC thereto. In this way, the drive electrode driver 14sequentially selects the drive electrode blocks B and applies the drivesignal for touch VcomAC thereto to scan the entire drive electrodeblocks B. The number of drive electrode blocks B is not limited totwenty.

In the touch detection unit 30, one of the drive electrode blocks Billustrated in FIG. 13 to FIG. 15 corresponds to a drive electrode E1 ina basic principle of the capacitive touch detection described above. Inthe touch detection unit 30, one of the touch detection electrodes TDLcorresponds to a touch detection electrode E2. The touch detection unit30 is configured to detect a touch according to the basic principledescribed above. As illustrated in FIG. 12, the electrode patternsintersecting with each other form a capacitive touch sensor in a matrix.Scanning the entire touch detection surface of the touch detecting unit30 enables detection of the position where the external contiguousobject is in contact or in contiguity with the device.

The display unit 10 with a touch detecting function drives the gatedriver 12 to perform line-sequential scanning on the scanning line GCLin a time division manner to perform display scanning. The display unit10 with a touch detecting function performs touch detection scanning, anoperation of which is completed when the drive electrode driver 14sequentially selects and drives each of the drive electrode blocks B.For example, a touch detection scanning Scant is performed at a scanningspeed of two times that of a display scanning Scand. In this way, in thedisplay device 1 with a touch detecting function, the scanning speed intouch detection is caused to be faster than the scanning speed indisplay to immediately respond to a touch by an external contiguousobject approaching from the outside, so that a response characteristicwith respect to the touch detection can be improved. A relation betweenthe touch detection scanning and the display scanning is not limitedthereto. For example, the touch detection scanning may be performed at ascanning speed two or more times faster than that of the displayscanning, or may be performed at a scanning speed not faster than thespeed of two times that of the display scanning.

Drive Signal Generation Unit and Drive Electrode Driver

FIG. 16 is a block diagram illustrating the drive signal generation unitof the drive electrode driver according to the first embodiment. A drivesignal generation unit 14Q includes a high-level voltage generation unit61, a low-level voltage generation unit 62, buffers 63, 64, and 66, anda switching circuit 65.

The high-level voltage generation unit 61 generates a high-level voltageof the drive signal for touch VcomAC. The low-level voltage generationunit 62 generates a direct current voltage of the drive voltage fordisplay VcomDC. The voltage generated by the low-level voltagegeneration unit 62 is also used as a low-level voltage of the drivesignal for touch VcomAC. The buffer 63 outputs the voltage supplied fromthe high-level voltage generation unit 61 while performing impedanceconversion thereon, and supplies the voltage to the switching circuit65. The buffer 64 outputs the voltage supplied from the low-levelvoltage generation unit 62 while performing impedance conversionthereon, and supplies the voltage to the switching circuit 65. Theswitching circuit 65 alternately repeats a case in which a drive controlsignal EXVCOM is high-level and a case in which the drive control signalEXVCOM is low-level based on the drive control signal EXVCOM, andgenerates the drive signal for touch VcomAC. The switching circuit 65outputs the voltage supplied from the buffer 63 when the drive controlsignal EXVCOM is high-level, and outputs the voltage supplied from thebuffer 64 when the drive control signal EXVCOM is low-level. Theswitching circuit 65 outputs the voltage supplied from the buffer 64 asthe direct current voltage of the drive voltage for display VcomDC whenthe drive control signal EXVCOM is low-level, based on the drive controlsignal EXVCOM. The buffers 63 and 64 include, for example, a voltagefollower. The voltage from the switching circuit 65 is output to anoutput terminal 65E. The buffer 66 outputs the voltage supplied from thelow-level voltage generation unit 62 while performing impedanceconversion thereon, and supplies the direct current voltage of the drivevoltage for display VcomDC to the output terminal 66E.

FIG. 17 is a block diagram illustrating the drive electrode driveraccording to the first embodiment. FIG. 18 is a block diagramillustrating a drive unit of the drive electrode driver according to thefirst embodiment. FIG. 19 is a block diagram illustrating a driveelectrode driver according to a comparative example. FIG. 20 is anexplanatory diagram schematically illustrating a width of wiring fortouch in a picture frame according to the comparative example. FIG. 21is an explanatory diagram schematically illustrating the width of thewiring for touch in the picture frame according to the first embodiment.

As illustrated in FIG. 17, the drive electrode scanning units 14A and14B include a scanning control unit 51, a touch detection scanning unit52, and a drive unit 530. The drive unit 530 includes drive units 53(k)to 53(k+3) the number of which is the same as that of the driveelectrode blocks B. The scanning control unit 51 is mounted on the COG19. The touch detection scanning unit 52 and the drive unit 530 arearranged in the picture frame at the periphery of the display area Ad.Hereinafter, to indicate any one of the drive units 53(k) to 53(k+3), a“drive unit 53” is simply referred to.

The scanning control unit 51 supplies a control signal SDCK and ascanning start signal SDST to the touch detection scanning unit 52 basedon the control signal supplied from the control unit 11. The drivevoltage for display VcomDC output from the drive signal generation unit14Q via the output terminal 66E is supplied to the wiring for displayLDC. The drive signal for touch VcomAC output from the drive signalgeneration unit 14Q via the output terminal 65E is supplied to thewiring for touch LAC. The scanning control unit 51 supplies, to thedrive unit 530, a drive electrode selection signal VCOMSEL to which thedrive signal for touch VcomAC is supplied from the drive signalgeneration unit 14Q. The drive electrode selection signal VCOMSEL is asignal for identifying a period in which the drive signal for touchVcomAC is supplied from the drive signal generation unit 14Q to thedrive electrode COML, that is, a touch detection period.

The touch detection scanning unit 52 includes a shift register for adrive electrode (first transfer circuit) 52SR1 and a shift register fora drive electrode (second transfer circuit) 52SR2 serving as transfercircuits. The shift register 52SR1 generates transfer circuit outputsSRout(k), SRout(k+1), SRout(k+2), SRout(k+3) . . . for selecting thedrive electrode COML to which the drive signal for touch VcomAC isapplied. Specifically, the touch detection scanning unit 52 causes thescanning start signal SDST as a trigger supplied from the scanningcontrol unit 51 to the shift register 52SR1 to be synchronized with thedrive electrode selection signal VCOMSEL so as to be sequentiallytransferred to the shift register 52SR2 next to the shift register 52SR1and be sequentially selected. The shift register 52SR2 generatestransfer circuit outputs TRN(k), TRN(k+1), TRN(k+2), TRN(k+3) . . . asidle transfer signals, and transfers the outputs to the next shiftregister 52SR1.

Herein, the idle transfer means that the transfer circuit output (shiftregister output) is not utilized for controlling a selection switch SW1(SW2, SW3, SW4) and the like, and is input to a transfer circuit in thenext stage or a transfer circuit to be coupled next.

The shift register 52SR1 selected in synchronization with the driveelectrode selection signal VCOMSEL sends out the transfer circuitoutputs SRout(k), SRout(k+1), SRout(k+2), SRout(k+3) . . . to eachamplification circuit 54 of the drive unit 530. In the touch detectionscanning unit 52, for example, when the selected shift register 52SRsupplies a high-level signal as the k+2-th transfer circuit outputSRout(k+2) to the k+2-th drive unit 53(k+2), the drive unit 53(k+2)applies the drive signal for touch VcomAC to a plurality of driveelectrodes COML belonging to the k+2-th drive electrode block B(k+2).Hereinafter, to indicate any one of the transfer circuit outputsSRout(k), SRout(k+1), SRout(k+2), SRout(k+3) . . . , a “transfer circuitoutput SRout” may be used. To indicate any of the transfer circuitoutputs TRN(k), TRN(k+1), TRN(k+2), TRN(k+3) . . . , a “transfer circuitoutput TRN” may be used.

The drive unit 530 is a circuit for applying the drive voltage fordisplay VcomDC or the drive signal for touch VcomAC supplied from thedrive signal generation unit 14Q to the drive electrode COML based onthe transfer circuit output SRout supplied from the touch detectionscanning unit 52 and the drive electrode selection signal VCOMSELsupplied from the scanning control unit 51. Each drive unit 53 isprovided corresponding to each output signal from the touch detectionscanning unit 52, and applies the drive signal Vcom to the correspondingdrive electrode block B.

The drive unit 53 includes the amplification circuit 54 and theselection switch SW1 (SW2, SW3, SW4) for each drive electrode block B.The transfer circuit output SRout supplied from the shift register 52SR1can control an operation of the selection switch SW1 (SW2, SW3, SW4) viathe amplification circuit 54 having a buffer function for amplifying theoutput to an amplitude level. That is, the operation of the selectionswitch SW1 (SW2, SW3, SW4) is controlled based on the signal suppliedfrom the shift register 52SR1. One end of the selection switch SW1 (SW2,SW3, SW4) is coupled to the drive electrodes COML included in the driveelectrode block B, and the other end of the selection switch SW1 iscoupled to one of the wiring for display LDC and the wiring for touchLAC.

With this configuration, the drive unit 53 outputs the drive signal fortouch VcomAC as the drive signal Vcom when the transfer circuit outputSRout is high-level and the drive electrode selection signal VCOMSEL ishigh-level. The drive unit 53 separates the drive electrode block B fromthe wiring for touch LAC to be coupled to the wiring for display LDCwhen transfer circuit output SRout is low-level and the drive electrodeselection signal VCOMSEL is low-level. Herein, the drive electrode blockB selected as an output destination of the drive signal for touch VcomACis a selection drive electrode block STX. The drive electrode block Bthat is not selected as the output destination of the drive signal fortouch VcomAC is a non-selection drive electrode block NTX. For example,the drive unit 53(k+2) illustrated in FIG. 17 applies the drive signalfor touch VcomAC to the drive electrodes COML belonging to the k+2-thdrive electrode block B(k+2), so that the selection drive electrodeblock STX is the drive electrode block B(k+2). The drive electrodeblocks B(k), B(k+1), and B(k+3) that are not selected as the outputdestination of the drive signal for touch VcomAC are non-selection driveelectrode blocks NTX.

When the liquid crystal display unit 20 performs a display operation,the transfer circuit output SRout of the drive unit 53 is low-level, andthe drive unit 53 couples each selection switch SW1 (SW2, SW3, SW4) tothe wiring for display LDC for each drive electrode block B to outputthe drive voltage for display VcomDC as the drive signal Vcom.

FIG. 18 is a block diagram illustrating the drive unit of the driveelectrode driver according to the first embodiment. Although FIG. 18illustrates a configuration of the first gate driver 12A, aconfiguration of the second gate driver 12B is similar thereto. Althoughthe following describes the selection switch SW1 as a representative,each of the selection switches SW2, SW3, and SW4 is similar thereto. Thefirst gate driver 12A (second gate driver 12B) includes a gate shiftregister 120SR. The gate shift register 120SR starts an operation inresponse to the vertical start pulse VST, is sequentially selected in avertical scanning direction in synchronization with a vertical clockVCK, and outputs a vertical selection pulse to the scanning line GCL viaa buffer circuit. As illustrated in FIG. 18, the size of the gate shiftregister 120SR increases corresponding to the number of sub-pixels SPix.Accordingly, one drive electrode COML overlaps with a plurality ofsub-pixels SPix in a direction intersecting with a direction in whichthe scanning line GCL extends, which is a direction in which the wiringfor touch LAC extends. As a result, the number of the gate shiftregisters 120SR for scanning the sub-pixels SPix overlapping with onedrive electrode COML in the direction in which the wiring for touch LACextends becomes larger than the number of shift registers 52SR1 for adrive electrode. As illustrated in FIG. 18, the shift register 52SR1 fora drive electrode and the shift register 52SR2 for a drive electrode arearranged side by side because there is a space in the direction in whichthe wiring for touch LAC extends. Due to this, the shift register 52SR2for a drive electrode can be formed in the picture frame area Gd inaddition to the shift register 52SR1 for a drive electrode withoutincreasing the picture frame area Gd.

The selection switch SW1 includes a plurality of switches COMSW for eachdrive electrode COML. All of the switches COMSW operate corresponding toswitch control signals Ssw and Sxsw for each drive electrode COML. Allof the switches COMSW operate for each drive electrode COML to selectany one of coupling between the wiring for touch LAC and the driveelectrode COML and coupling between the wiring for display LDC and thedrive electrode COML in a time-division manner.

In the switch COMSW, for example, when a CMOS switch CMOS1 and a CMOSswitch CMOS2 are assumed to be one circuit unit, a plurality of circuitunits are provided for each drive electrode COML. Each of the CMOSswitch CMOS1 and the CMOS switch CMOS2 includes a transistor NMOS havingan N-channel gate and a transistor PMOS having a P-channel gate.

In the CMOS switch CMOS1, a switch signal line GSW is coupled to thegates of the transistor NMOS and the transistor PMOS. In the CMOS switchCMOS2, a switch signal line GxSW is coupled to the gates of thetransistor NMOS and the transistor PMOS. The switch control signal Sswsupplied to the switch signal line GSW and the switch control signalSxsw supplied to the switch signal line GxSW are signals in which theelectric potential is reversed between high-level and low-level. Due tothis, the CMOS switch CMOS1 and the CMOS switch CMOS2 can perform thesame selection by synchronizing any one of the coupling between thewiring for touch LAC and the drive electrode COML and the couplingbetween the wiring for display LDC and the drive electrode COML. In thisway, the selection switch SW1 includes the switches COMSW for each driveelectrode COML, and the switches COMSW are coupled in parallel betweenthe wiring for touch LAC and the drive electrode COML. All of theswitches COMSW operate for each drive electrode COML corresponding tothe switch control signals Ssw and Sxsw serving as selection signals,couple the wiring for touch LAC to the drive electrode COML, and applythe drive signal for touch VcomAC.

The amplification circuit 54 includes an inverter, a switching circuit,and a buffer. The inverter outputs inverted logic of the transfercircuit output SRout at a selected transfer stage among the shiftregisters 52SR1 for a drive electrode when the transfer circuit outputSRout is high-level. The amplification circuit 54 switches from theinput and the output of the inverter corresponding to the driveelectrode selection signal VCOMSEL and outputs the switch control signalSsw to the buffer. The buffer amplifies the switch control signal Ssw tobe supplied to the switch signal line GSW. The inverter generates theinverted logic of the switch control signal Ssw output from the bufferand outputs the inverted logic as the switch control signal Sxsw to besupplied to the switch signal line GxSW.

The CMOS switches CMOS1 and CMOS2 are coupled to the wiring for touchLAC with a coupling conductor Q3. The CMOS switches CMOS1 and CMOS2 arecoupled to the wiring for display LDC with a coupling conductor Q2. TheCMOS switches CMOS1 and CMOS2 are coupled to the drive electrode COMLwith the coupling conductor Q1. In the CMOS switches CMOS1 and CMOS2,when the switch control signals Ssw and Sxsw are input to the gates ofthe transistor NMOS and the transistor PMOS, any one of the couplingbetween the coupling conductor Q1 and the coupling conductor Q2 and thecoupling between the coupling conductor Q3 and the coupling conductor Q1can be selected.

As illustrated in FIG. 18, basically, the scanning line GCL is wired inthe same layer as the switch signal lines GSW and GxSW. At anintersecting portion of the scanning line GCL and the switch signallines GSW and GxSW, they intersect with each other in a grade separatedmanner via an insulating layer. The scanning line GCL is a gate line ofthe same transistor as the switch signal lines GSW and GxSW. Amanufacturing process of the scanning line GCL can be shortened by beingformed through the same process as the switch signal lines GSW and GxSW.The scanning line GCL intersects with the wiring for touch LAC and thewiring for display LDC in a grade separated manner via the insulatinglayer. The selection switch SW1 is arranged in an area between thescanning lines GCL intersecting with the wiring for touch LAC (wiringfor display LDC) (for example, between the scanning line GCL_(m+1) andthe scanning line GCL_(m+2)). A space between the scanning lines GCLintersecting with the wiring for touch LAC (wiring for display LDC) isthe same as a space between the scanning lines GCL adjacent to eachother in the display area Ad.

COMPARATIVE EXAMPLE

As illustrated in FIG. 19, the touch detection scanning unit 52 includesthe shift register 52SR1 for a drive electrode serving as a transfercircuit, and does not include the shift register 52SR2 for a driveelectrode. The shift register 52SR1 for a drive electrode generatestransfer circuit outputs SRout(k), SRout(k+1), SRout(k+2), SRout(k+3) .. . for selecting the drive electrode COML to which the drive signal fortouch VcomAC is applied. Specifically, the touch detection scanning unit52 causes the scanning start signal SDST as a trigger supplied from thescanning control unit 51 to the shift register 52SR1 to be synchronizedwith control signals SDCK1 and SDCK2 so as to be sequentiallytransferred for each transfer stage of the shift register 52SR2 and besequentially selected. The selected shift register 52SR sends out thetransfer circuit outputs SRout(k), SRout(k+1), SRout(k+2), SRout(k+3) .. . to each logic circuit 55 of the drive unit 530. The logic circuit 55generates and outputs a logical product (AND) of the transfer circuitoutput SRout supplied from the touch detection scanning unit 52 and thedrive electrode selection signal VCOMSEL supplied from the scanningcontrol unit 51. The logic circuit 55 has a buffer function foramplifying the amplitude to a level that can control the operation ofthe selection switch SW1 (SW2, SW3, SW4). In the touch detectionscanning unit 52, when the selected shift register 52SR supplies, forexample, a high-level signal to the k+2-th drive unit 53(k+2) as thek+2-th transfer circuit output SRout(k+2), the drive unit 53(k+2)applies the drive signal VcomAC to the drive electrodes COML belongingto the k+2-th drive electrode block B(k+2).

As illustrated in FIG. 20, in the picture frame area Gd, the wiring fordisplay LDC and the wiring for touch LAC occupy a width Wtp and a wiringarea of the drive unit 53 occupies a width Wtx. Resistance of the wiringfor touch LAC is desired to be suppressed. For example, because theresistance of the wiring for touch LAC is the maximum at the driveelectrode COML farther than the output terminal 65E, a waveform of thedrive signal for touch VcomAC may be distorted corresponding to a timeconstant and may influence accuracy in touch detection. The influence ofthe resistance of the wiring for touch LAC on the time constant is abouttwo times greater than the influence of the drive electrode COML fartherthan the output terminal 65E thereon. Accordingly, it is effective toincrease the width of the wiring for touch LAC and suppresses theresistance of the wiring for touch LAC to the drive electrode COMLfarther than the output terminal 65E. However, increase in the width Wtpmay cause increase in the picture frame area Gd, so that the pictureframe that does not contribute to the display area may be unfortunatelyenlarged.

As illustrated in FIG. 20, the width Wtx includes a control signal lineLSDST for transmitting the scanning start signal SDST, a control signalline LSDCK1 for transmitting the control signal SDCK1, a control signalline LSDCK2 for transmitting the control signal SDCK2, a control signalline LVCOMSEL for transmitting the drive electrode selection signalVCOMSEL, a formation area of the shift register 52SR1, power supplylines LPWA and LPWB for a logic circuit for a Logic power supply thatdrives the shift register 52SR1 and the like, and a space forinter-wiring insulation. A width ΔWCK including the control signal lineLSDCK1, the control signal line LSDCK2, and the space for inter-wiringinsulation is required to be substantially 15 μm to 20 μm, for example.

As illustrated in FIG. 21, the width Wtx according to the firstembodiment includes the control signal line LSDST for transmitting thescanning start signal SDST, the control signal line LVCOMSEL fortransmitting the drive electrode selection signal VCOMSEL, the formationarea of the shift register 52SR1, the power supply lines for a logiccircuit LPWA and LPWB for the Logic power supply that drives the shiftregister 52SR1 and the like, and the space for inter-wiring insulation.The width Wtx according to the first embodiment does not include thecontrol signal line LSDCK1 for transmitting the control signal SDCK1 andthe control signal line LSDCK2 for transmitting the control signalSDCK2, so that the width Wtx according to the first embodiment can bereduced by the width ΔWCK illustrated in FIG. 20. Due to this, thepicture frame area Gd according to the first embodiment can be narrowed.The wiring for touch LAC can be increased by a width Δwl illustrated inFIG. 21 corresponding to the width ΔWCK illustrated in FIG. 20. When thewiring for touch LAC is increased by the width Δwl illustrated in FIG.21 corresponding to the width ΔWCK illustrated in FIG. 20, theresistance of the wiring for touch LAC is reduced. As a result, thewaveform distortion of the drive signal for touch VcomAC is improved andthe accuracy in touch detection can be enhanced. Alternatively, when thewiring for touch LAC is increased by the width Δwl illustrated in FIG.21 corresponding to part of the width ΔWCK illustrated in FIG. 20, thewaveform distortion of the drive signal for touch VcomAC is improved,the accuracy in touch detection is enhanced, and the picture frame areaGd can be narrowed.

The following describes an operation and advantageous effects of thedisplay device 1 with a touch detecting function according to the firstembodiment. In the following description, the drive signal Vcom servingas the display drive signal is referred to as the drive voltage fordisplay VcomDC, and the drive signal Vcom serving as the drive signalfor touch detection is referred to as the drive signal for touch VcomAC.

Operation of Display Device with Touch Detecting Function

Next, the following describes an operation of the display device 1 witha touch detecting function. FIG. 22 is an explanatory diagramillustrating an example of a timing waveform of the display device witha touch detecting function. As illustrated in FIG. 22, the displaydevice 1 with a touch detecting function according to the firstembodiment separately performs a touch detection operation (touchdetection operation period) and a display operation (display period).The touch detection operation period illustrated in FIG. 22 includesTouch Term 1, Touch Term 2, and Touch Term 3. The display periodincludes Disply Term 1, Disply Term 2, and Disply Term 3. The touchdetection operation period and the display period are alternatelyoperated.

When the scanning start signal SDST is input, the shift register 52SR1outputs the transfer circuit output SRout1 as high-level insynchronization with high-level of the drive electrode selection signalVCOMSEL using the scanning start signal SDST as a trigger. When thedrive electrode selection signal VCOMSEL is high-level, the drive unit53 outputs the drive signal for touch VcomAC as a waveform Tx1 of thedrive signal Vcom. When the shift register 52SR1 outputs the transfercircuit output SRout1 as low-level, the shift register 52SR2 receivesthe transfer circuit output SRout1 and performs idle transfer to outputa transfer circuit output TRN1. When the drive electrode selectionsignal VCOMSEL is low-level, the drive unit 53 switches the drive signalfor touch VcomAC to the drive signal for display VcomDC to be output asthe drive signal Vcom.

The high-level of the transfer circuit output TRN1 overlaps with thehigh-level of the next drive electrode selection signal VCOMSELcorresponding to a signal delay, so that the next shift register 52SR1outputs the transfer circuit output SRout2 as high-level insynchronization with the high-level of the drive electrode selectionsignal VCOMSEL using a logical product of the high-level of the transfercircuit output TRN1 and the high-level of the drive electrode selectionsignal VCOMSEL as a trigger. When the drive electrode selection signalVCOMSEL is high-level, the drive unit 53 outputs the drive signal fortouch VcomAC as a waveform Tx2 of the drive signal Vcom. When the shiftregister 52SR1 outputs the transfer circuit output SRout2 as low-level,the shift register 52SR2 receives the transfer circuit output SRout2 andperforms idle transfer to output a transfer circuit output TRN2. Whenthe drive electrode selection signal VCOMSEL is low-level, the driveunit 53 switches the drive signal for touch VcomAC to the drive signalfor display VcomDC to be output as the drive signal Vcom.

The high-level of the transfer circuit output TRN2 overlaps with thehigh-level of the next drive electrode selection signal VCOMSELcorresponding to a signal delay, so that the next shift register 52SR1outputs the transfer circuit output SRout3 as high-level insynchronization with the high-level of the drive electrode selectionsignal VCOMSEL using a logical product of the high-level of the transfercircuit output TRN2 and the high-level of the drive electrode selectionsignal VCOMSEL as a trigger. When the drive electrode selection signalVCOMSEL is high-level, the drive unit 53 outputs the drive signal fortouch VcomAC as a waveform Tx3 of the drive signal Vcom. When the shiftregister 52SR1 outputs the transfer circuit output SRout3 as low-level,the shift register 52SR2 receives the transfer circuit output SRout3 andperforms idle transfer to output a transfer circuit output TRN3. Whenthe drive electrode selection signal VCOMSEL is low-level, the driveunit 53 switches the drive signal for touch VcomAC to the drive signalfor display VcomDC to be output as the drive signal Vcom. Thereafter,the operation of the display device 1 with a touch detecting functionwill be repeated. In this way, the selection drive electrode block STXto which the drive signal for touch VcomAC is supplied is selectedcorresponding to change in the level of the drive electrode selectionsignal VCOMSEL that identifies an operation period for touch detection.

Modification

FIG. 23 is an explanatory diagram illustrating a modification of thetiming waveform of the display device with a touch detecting function.As illustrated in FIG. 23, the display device 1 with a touch detectingfunction according to the modification separately performs a touchdetection operation (touch detection operation period) and a displayoperation (display period). The touch detection operation periodillustrated in FIG. 23 includes Touch Term 1, Touch Term 2, and TouchTerm 3. The display period includes Disply Term 1, Disply Term 2, andDisply Term 3. The touch detection operation period and the displayperiod are alternately operated.

When the scanning start signal SDST is input, the shift register 52SR1outputs the transfer circuit output SRout1 as high-level insynchronization with low-level of the drive electrode selection signalVCOMSEL using the scanning start signal SDST as a trigger. When thedrive electrode selection signal VCOMSEL is low-level, the drive unit 53outputs the drive signal for touch VcomAC as the waveform Tx1 of thedrive signal Vcom. When the shift register 52SR1 outputs the transfercircuit output SRout1 as low-level, the shift register 52SR2 receivesthe transfer circuit output SRout1 and performs idle transfer to outputthe transfer circuit output TRN1. When the drive electrode selectionsignal VCOMSEL is high-level, the drive unit 53 switches the drivesignal for touch VcomAC to the drive signal for display VcomDC to beoutput as the drive signal Vcom.

The high-level of the transfer circuit output TRN1 overlaps with thelow-level of the next drive electrode selection signal VCOMSELcorresponding to a signal delay, so that the next shift register 52SR1outputs the transfer circuit output SRout2 as high-level insynchronization with the low-level of the drive electrode selectionsignal VCOMSEL using a logical sum of the high-level of the transfercircuit output TRN1 and the low-level of the drive electrode selectionsignal VCOMSEL as a trigger. When the drive electrode selection signalVCOMSEL is low-level, the drive unit 53 outputs the drive signal fortouch VcomAC as the waveform Tx2 of the drive signal Vcom. When theshift register 52SR1 outputs the transfer circuit output SRout2 aslow-level, the shift register 52SR2 receives the transfer circuit outputSRout2 and performs idle transfer to output a transfer circuit outputTRN2. When the drive electrode selection signal VCOMSEL is high-level,the drive unit 53 switches the drive signal for touch VcomAC to thedrive signal for display VcomDC to be output as the drive signal Vcom.

The high-level of the transfer circuit output TRN2 overlaps with thelow-level of the next drive electrode selection signal VCOMSELcorresponding to a signal delay, so that the next shift register 52SR1outputs the transfer circuit output SRout3 as high-level insynchronization with the low-level of the drive electrode selectionsignal VCOMSEL using a logical sum of the high-level of the transfercircuit output TRN2 and the low-level of the drive electrode selectionsignal VCOMSEL as a trigger. When the drive electrode selection signalVCOMSEL is low-level, the drive unit 53 outputs the drive signal fortouch VcomAC as the waveform Tx3 of the drive signal Vcom. When theshift register 52SR1 outputs the transfer circuit output SRout3 aslow-level, the shift register 52SR2 receives the transfer circuit outputSRout3 and performs idle transfer to output the transfer circuit outputTRN3. When the drive electrode selection signal VCOMSEL is high-level,the drive unit 53 switches the drive signal for touch VcomAC to thedrive signal for display VcomDC to be output as the drive signal Vcom.Thereafter, the operation of the display device 1 with a touch detectingfunction will be repeated.

As described above, the display device 1 with a touch detecting functionaccording to the first embodiment includes the display area Ad in whichthe pixel electrodes are arranged in a matrix on the TFT substrate 21,the drive electrode COML that is divided into a plurality of pieces andarranged opposed to the pixel electrodes, and the liquid crystal layer 6serving as the display function layer having the image display functionfor displaying an image in the display area Ad. The control deviceaccording to the first embodiment includes the control unit 11, the gatedriver 12, the source driver 13, and the drive electrode driver 14. Thecontrol device performs image display control for exhibiting the imagedisplay function by applying the drive voltage for display VcomDCbetween the pixel electrode and the drive electrode COML based on theimage signal. The display device 1 with a touch detecting functionaccording to the first embodiment includes the touch detection electrodethat is opposed to the drive electrode COML and forms capacitancebetween the drive electrode COML and the touch detection electrode, thetouch detection unit that detects the position of the contiguous objectbased on the detection signal from the touch detection electrode, thewiring for touch LAC that is arranged in the picture frame area Gdpositioned on the outside of the display area and supplies the drivesignal for touch VcomAC to the drive electrode COML, and the selectionswitch SW that selects the drive electrode COML to be coupled to thewiring for touch LAC. The shift registers 52SR1 and 52SR2 include theshift register 52SR1 serving as the first transfer circuit and the shiftregister 52SR2 serving as the second transfer circuit. The shiftregister 52SR1 serving as the first transfer circuit is a transfercircuit that controls the selection switch SW1 (SW2, SW3, SW4). Theshift register 52SR2 serving as the second transfer circuit supplies thetransfer circuit output to the shift register 52SR1.

In other words, the drive electrode scanning units 14A and 14B of thedrive electrode driver 14 among the control devices select the driveelectrode COML to which the drive signal for touch VcomAC is suppliedfrom among the drive electrodes COML in the scanning direction Scan. Thedrive electrode scanning units 14A and 14B for selecting one driveelectrode COML include the shift registers 52SR1 and 52SR2 serving asthe transfer circuits in the picture frame area Gd to select the driveelectrode COML to which the drive signal for touch VcomAC is suppliedfrom among the drive electrodes COML. The shift register 52SR1 that ispart of the shift registers 52SR1 and 52SR2 is the transfer circuit forthe output to the selection switch SW1 (SW2, SW3, SW4).

Accordingly, the picture frame area Gd according to the first embodimentcan be narrowed. The entire circuits in the picture frame area Gd can bebrought near the display area Ad, and quality can be improved bypreventing infiltration of water or cracking. The picture frame area Gdaccording to the first embodiment can also reduce the resistance of thewiring for touch LAC. As a result, the waveform distortion of the drivesignal for touch VcomAC is improved and the accuracy in touch detectioncan be enhanced. The circuit for generating the control signals SDCK1and SDCK2 becomes unnecessary and the size of the circuit of the COG 19is reduced, so that an IC can be downsized. The picture frame area Gdaccording to the first embodiment can also reduce the resistance of thewiring for touch LAC and narrow the picture frame area Gd.

The shift registers 52SR1 and 52SR2 are arranged side by side in adirection in which the wiring for touch LAC extends. Due to this, theshift registers 52SR1 and 52SR2 can be arranged without widening thepicture frame area Gd. Regarding the drive electrode scanning units 14Aand 14B for selecting one drive electrode COML, the two shift registers52SR1 and 52SR2 are exemplified as the transfer circuits for selectingthe drive electrode COML to which the drive signal for touch VcomAC issupplied from among the drive electrodes COML. However, the number ofthe transfer circuits is not limited thereto. For example, the driveelectrode scanning units 14A and 14B for selecting one drive electrodeCOML may include three transfer circuits: one shift register 52SR1, andtwo shift registers 52SR2. Due to this, a period of idle transfer can beprolonged. Alternatively, the drive electrode scanning units 14A and 14Bfor selecting one drive electrode COML may include a plurality oftransfer circuits: two or more shift registers 52SR1, and two or moreshift registers 52SR2.

The gate shift registers 120SR serving as the transfer circuits fordisplay that scan the pixel electrode are arranged in the picture framearea Gd. The number of shift registers 52SR1 and 52SR2 provided for onedrive electrode COML may be smaller than that of the gate shiftregisters 120SR for scanning the pixel electrode that overlap with onedrive electrode COML. Due to this, the shift registers 52SR1 and 52SR2can be arranged without widening the picture frame area Gd.

The wiring for display LDC for supplying the drive voltage for displayVcomDC and the wiring for touch LAC for supplying the drive signal fortouch VcomAC are arranged in parallel. Due to this, a voltage can besupplied to the drive electrode COML by effectively using the pictureframe area Gd.

The shift registers 52SR1 and 52SR2 for selecting the drive electrodeCOML to which the drive signal for touch VcomAC is supplied from amongthe drive electrodes COML are provided in the picture frame area Gd foreach drive electrode COML. Among the shift registers 52SR1 and 52SR2,the shift register 52SR2 different from the shift register 52SR1 is thetransfer circuit for outputting a signal of the transfer circuit outputTRN as idle transfer. Accordingly, as illustrated in FIG. 7, the driveelectrode driver 14 can scan the drive electrode block B (one detectionblock) of the drive electrode COML in the scanning direction Scan evenwhen there are no control signals SDCK1 and SDCK2 serving as timingpulses.

The drive electrode selection signal VCOMSEL for identifying theoperation period for touch detection is input to the shift registers52SR1 and 52SR2 serving as the transfer circuits. Accordingly, asillustrated in FIG. 7, the drive electrode driver 14 can scan the driveelectrode block B (one detection block) of the drive electrode COML inthe scanning direction Scan even when there are no control signals SDCK1and SDCK2 serving as timing pulses.

The picture frame area Gd includes the control signal line LVCOMSEL fortransmitting the drive electrode selection signal VCOMSEL thatidentifies the operation period for touch detection, and the controlsignal line LVCOMSEL is coupled to the shift registers 52SR1 and 52SR2.Due to this, the picture frame area Gd can be narrowed. The wiring fortouch LAC can be increased by the width Δwl illustrated in FIG. 21corresponding to the width ΔWCK illustrated in FIG. 20. When the wiringfor touch LAC is increased by the width Δwl illustrated in FIG. 21corresponding to the width ΔWCK illustrated in FIG. 20, the resistanceof the wiring for touch LAC is reduced. As a result, the waveformdistortion of the drive signal for touch VcomAC is improved and theaccuracy in touch detection can be enhanced.

Second Embodiment

The following describes a display device 1 with a touch detectingfunction according to a second embodiment. Components similar to thoseof the first embodiment are denoted by the same reference numerals, andan overlapping explanation thereof will be omitted. FIG. 24 is a blockdiagram illustrating the drive electrode driver according to the secondembodiment. As illustrated in FIG. 24, the touch detection scanning unit52 generates the transfer circuit output TRN(k) serving as an idletransfer signal using the scanning start signal SDST supplied to theshift register 52SR2 from the scanning control unit 51 as a trigger, andtransfers the transfer circuit output TRN(k) to the next shift register52SR1. The shift register 52SR1 to which the transfer circuit outputTRN(k) is transferred synchronizes the transfer circuit output TRN(k)with the drive electrode selection signal VCOMSEL to be sequentiallytransferred to the shift register 52SR2 next to the shift register 52SR1and be sequentially selected. The shift register 52SR2 generates thetransfer circuit outputs TRN(k+1), TRN(k+2), TRN(k+3) . . . as idletransfer signals to be transferred to the next shift register 52SR1.

Next, the following describes an operation of the display device 1 witha touch detecting function. FIG. 25 is an explanatory diagramillustrating an example of the timing waveform of the display devicewith a touch detecting function according to the second embodiment.

When the scanning start signal SDST is input, the shift register 52SR2performs idle transfer using the scanning start signal SDST as atrigger, and outputs the transfer circuit output TRN1. The high-level ofthe transfer circuit output TRN1 overlaps with the high-level of thenext drive electrode selection signal VCOMSEL corresponding to a signaldelay, so that the next shift register 52SR1 outputs the transfercircuit output SRout1 as high-level in synchronization with thehigh-level of the drive electrode selection signal VCOMSEL using alogical product of the high-level of the transfer circuit output TRN1and the high-level of the drive electrode selection signal VCOMSEL as atrigger. When the drive electrode selection signal VCOMSEL ishigh-level, the drive unit 53 outputs the drive signal for touch VcomACas the waveform Tx1 of the drive signal Vcom. When the shift register52SR1 outputs the transfer circuit output SRout1 as low-level, the shiftregister 52SR2 receives the transfer circuit output SRout1 and performsidle transfer to output the transfer circuit output TRN2. When the driveelectrode selection signal VCOMSEL is low-level, the drive unit 53switches the drive signal for touch VcomAC to the drive signal fordisplay VcomDC to be output as the drive signal Vcom.

The high-level of the transfer circuit output TRN2 overlaps with thehigh-level of the next drive electrode selection signal VCOMSELcorresponding to a signal delay, so that the next shift register 52SR1outputs the transfer circuit output SRout2 as high-level insynchronization with the high-level of the drive electrode selectionsignal VCOMSEL using a logical product of the high-level of the transfercircuit output TRN2 and the high-level of the drive electrode selectionsignal VCOMSEL as a trigger. When the drive electrode selection signalVCOMSEL is high-level, the drive unit 53 outputs the drive signal fortouch VcomAC as the waveform Tx2 of the drive signal Vcom. When theshift register 52SR1 outputs the transfer circuit output SRout2 aslow-level, the shift register 52SR2 receives the transfer circuit outputSRout2 and performs idle transfer to output a transfer circuit outputTRN3. When the drive electrode selection signal VCOMSEL is low-level,the drive unit 53 switches the drive signal for touch VcomAC to thedrive signal for display VcomDC to be output as the drive signal Vcom.

The high-level of the transfer circuit output TRN3 overlaps with thehigh-level of the next drive electrode selection signal VCOMSELcorresponding to a signal delay, so that the next shift register 52SR1outputs the transfer circuit output SRout3 as high-level insynchronization with the high-level of the drive electrode selectionsignal VCOMSEL using a logical product of the high-level of the transfercircuit output TRN3 and the high-level of the drive electrode selectionsignal VCOMSEL as a trigger. When the drive electrode selection signalVCOMSEL is high-level, the drive unit 53 outputs the drive signal fortouch VcomAC as a waveform Tx3 of the drive signal Vcom. When the shiftregister 52SR1 outputs the transfer circuit output SRout3 as low-level,the shift register 52SR2 receives the transfer circuit output SRout3 andperforms idle transfer to output a transfer circuit output TRN3. Whenthe drive electrode selection signal VCOMSEL is low-level, the driveunit 53 switches the drive signal for touch VcomAC to the drive signalfor display VcomDC to be output as the drive signal Vcom. Thereafter,the operation of the display device 1 with a touch detecting functionwill be repeated.

Modification

FIG. 26 is a block diagram illustrating the drive electrode driveraccording to a modification of the second embodiment. FIG. 27 is anexplanatory diagram illustrating an example of the timing waveform ofthe display device with a touch detecting function according to themodification of the second embodiment. As illustrated in FIG. 26, in thedrive electrode driver according to the modification of the secondembodiment, a shift register at the first stage that acquires thescanning start signal SDST is the shift register 52SR1. Due to this, thenumber of circuits is reduced.

Accordingly, as illustrated in FIG. 27, when the scanning start signalSDST is input, the shift register 52SR1 outputs the transfer circuitoutput SRout1 as high-level in synchronization with high-level of thedrive electrode selection signal VCOMSEL using the scanning start signalSDST as a trigger. When the drive electrode selection signal VCOMSEL ishigh-level, the drive unit 53 outputs the drive signal for touch VcomACas the waveform Tx1 of the drive signal Vcom. When the shift register52SR1 outputs the transfer circuit output SRoutl as low-level, the shiftregister 52SR2 receives the transfer circuit output SRout1 and performsidle transfer to output the transfer circuit output TRN2. When the driveelectrode selection signal VCOMSEL is low-level, the drive unit 53switches the drive signal for touch VcomAC to the drive signal fordisplay VcomDC to be output as the drive signal Vcom.

The high-level of the transfer circuit output TRN2 overlaps with thehigh-level of the next drive electrode selection signal VCOMSELcorresponding to a signal delay, so that the next shift register 52SR1outputs the transfer circuit output SRout2 as high-level insynchronization with the high-level of the drive electrode selectionsignal VCOMSEL using a logical product of the high-level of the transfercircuit output TRN2 and the high-level of the drive electrode selectionsignal VCOMSEL as a trigger. When the drive electrode selection signalVCOMSEL is high-level, the drive unit 53 outputs the drive signal fortouch VcomAC as the waveform Tx2 of the drive signal Vcom. When theshift register 52SR1 outputs the transfer circuit output SRout2 aslow-level, the shift register 52SR2 receives the transfer circuit outputSRout2 and performs idle transfer to output a transfer circuit outputTRN3. When the drive electrode selection signal VCOMSEL is low-level,the drive unit 53 switches the drive signal for touch VcomAC to thedrive signal for display VcomDC to be output as the drive signal Vcom.

The high-level of the transfer circuit output TRN3 overlaps with thehigh-level of the next drive electrode selection signal VCOMSELcorresponding to a signal delay, so that the next shift register 52SR1outputs the transfer circuit output SRout3 as high-level insynchronization with the high-level of the drive electrode selectionsignal VCOMSEL using a logical product of the high-level of the transfercircuit output TRN3 and the high-level of the drive electrode selectionsignal VCOMSEL as a trigger. When the drive electrode selection signalVCOMSEL is high-level, the drive unit 53 outputs the drive signal fortouch VcomAC as a waveform Tx3 of the drive signal Vcom. When the shiftregister 52SR1 outputs the transfer circuit output SRout3 as low-level,the shift register 52SR2 receives the transfer circuit output SRout3 andperforms idle transfer to output a transfer circuit output TRN3. Whenthe drive electrode selection signal VCOMSEL is low-level, the driveunit 53 switches the drive signal for touch VcomAC to the drive signalfor display VcomDC to be output as the drive signal Vcom. Thereafter,the operation of the display device 1 with a touch detecting functionwill be repeated.

Third Embodiment

The following describes a display device 1 with a touch detectingfunction according to a third embodiment. Components similar to those ofthe first embodiment are denoted by the same reference numerals, and anoverlapping explanation thereof will be omitted. FIG. 28 is a blockdiagram illustrating the drive electrode driver according to the thirdembodiment. FIG. 29 is a block diagram illustrating the drive signalgeneration unit of the drive electrode driver according to the thirdembodiment.

As illustrated in FIG. 28, the drive unit 53 according to the thirdembodiment includes the logic circuit 55 described in the firstembodiment. Accordingly, as illustrated in FIG. 29, the drive signalgeneration unit 14Q includes the high-level voltage generation unit 61,the low-level voltage generation unit 62, and the buffers 63 and 64. Thehigh-level voltage generation unit 61 outputs a high-level directcurrent voltage of the high-level drive signal VcomDCH to the outputterminal 65E via the buffer 63. The low-level voltage generation unit 62outputs the direct current voltage of the drive voltage for displayVcomDC to the output terminal 66E via the buffer 64. As illustrated inFIG. 28, the logic circuit 55 generates and outputs a logical product(AND) of the transfer circuit output SRout supplied from the touchdetection scanning unit 52 and the drive control signal EXVCOM suppliedfrom the scanning control unit 51. The logic circuit 55 has a bufferfunction for amplifying the amplitude to a level that can control theoperation of the selection switch SW1 (SW2, SW3, SW4). In the touchdetection scanning unit 52, when the selected shift register 52SRsupplies, for example, a high-level signal to the k+2-th drive unit53(k+2) as the k+2-th transfer circuit output SRout(k+2), the drive unit53(k+2) applies the drive signal VcomAC to the drive electrodes COMLbelonging to the k+2-th drive electrode block B(k+2). The output fromthe logic circuit 55 controls the operation of the selection switch SW1(SW2, SW3, SW4) when the drive control signal EXVCOM is high-level, anda voltage supplied from the output terminal 65E is output to the driveelectrode COML. The output from the logic circuit 55 controls theoperation of the selection switch SW1 (SW2, SW3, SW4) when the drivecontrol signal EXVCOM is low-level, and a voltage supplied from theoutput terminal 66E is output to the drive electrode COML. As a result,a case in which the drive control signal EXVCOM is high-level and a casein which the drive control signal EXVCOM is low-level are alternatelyrepeated, and the drive signal for touch VcomAC is generated. The logiccircuit 55 outputs the voltage supplied from the buffer 64 as the directcurrent voltage of the drive voltage for display VcomDC when the drivecontrol signal EXVCOM is low-level based on the drive control signalEXVCOM.

The display device 1 with a touch detecting function according to thethird embodiment does not include the control signal line LSDCK1 fortransmitting the control signal SDCK1 and the control signal line LSDCK2for transmitting the control signal SDCK2, so that the width Wtxaccording to the third embodiment can be reduced by the width ΔWCKillustrated in FIG. 20. Accordingly, the wiring for touch LAC can beincreased by the width corresponding to the width ΔWCK illustrated inFIG. 20. When the wiring for touch LAC is increased by the widthcorresponding to the width ΔWCK illustrated in FIG. 20, the resistanceof the wiring for touch LAC is reduced. As a result, the waveformdistortion of the drive signal for touch VcomAC is improved and theaccuracy in touch detection can be enhanced. Alternatively, when thewiring for touch LAC is increased by the width Δwl illustrated in FIG.21 corresponding to part of the width ΔWCK illustrated in FIG. 20, thewaveform distortion of the drive signal for touch VcomAC is improved,the accuracy in touch detection is enhanced, and the picture frame areaGd can be narrowed.

Next, the following describes the operation of the display device 1 witha touch detecting function. FIG. 30 is an explanatory diagramillustrating an example of the timing waveform of the display devicewith a touch detecting function according to the third embodiment.

When the scanning start signal SDST is input, the shift register 52SR1outputs the transfer circuit output SRout1 as high-level insynchronization with high-level of the drive electrode selection signalVCOMSEL using the scanning start signal SDST as a trigger. When thedrive electrode selection signal VCOMSEL is high-level, a case in whichthe drive control signal EXVCOM is high-level and a case in which thedrive control signal EXVCOM is low-level are alternately repeated basedon the drive control signal EXVCOM supplied from the scanning controlunit 51, and the drive unit 53 generates the drive signal for touchVcomAC from the high-level drive signal VcomDCH and the drive voltagefor display VcomDC to output the drive signal for touch VcomAC as thewaveform Tx1 of the drive signal Vcom. When the shift register 52SR1outputs the transfer circuit output SRout1 as low-level, the shiftregister 52SR2 receives the transfer circuit output SRout2 and performsidle transfer to output the transfer circuit output TRN1. When the driveelectrode selection signal VCOMSEL is low-level, the drive unit 53switches the drive signal for touch VcomAC to the drive signal fordisplay VcomDC to be output as the drive signal Vcom.

The high-level of the transfer circuit output TRN1 overlaps with thehigh-level of the next drive electrode selection signal VCOMSELcorresponding to a signal delay, so that the next shift register 52SR1outputs the transfer circuit output SRout2 as high-level insynchronization with the high-level of the drive electrode selectionsignal VCOMSEL using a logical product of the high-level of the transfercircuit output TRN1 and the high-level of the drive electrode selectionsignal VCOMSEL as a trigger. When the drive electrode selection signalVCOMSEL is high-level, the drive unit 53 generates the drive signal fortouch VcomAC, and outputs the drive signal for touch VcomAC as thewaveform Tx2 of the drive signal Vcom. When the shift register 52SR1outputs the transfer circuit output SRout2 as low-level, the shiftregister 52SR2 receives the transfer circuit output SRout2 and performsidle transfer to output the transfer circuit output TRN2. When the driveelectrode selection signal VCOMSEL is low-level, the drive unit 53switches the drive signal for touch VcomAC to the drive signal fordisplay VcomDC to be output as the drive signal Vcom.

The high-level of the transfer circuit output TRN2 overlaps with thehigh-level of the next drive electrode selection signal VCOMSELcorresponding to a signal delay, so that the next shift register 52SR1outputs the transfer circuit output SRout3 as high-level insynchronization with the high-level of the drive electrode selectionsignal VCOMSEL using a logical product of the high-level of the transfercircuit output TRN2 and the high-level of the drive electrode selectionsignal VCOMSEL as a trigger. When the drive electrode selection signalVCOMSEL is high-level, the drive unit 53 generates the drive signal fortouch VcomAC, and outputs the drive signal for touch VcomAC as thewaveform Tx3 of the drive signal Vcom. When the shift register 52SR1outputs the transfer circuit output SRout3 as low-level, the shiftregister 52SR2 receives the transfer circuit output SRout3 and performsidle transfer to output the transfer circuit output TRN3. When the driveelectrode selection signal VCOMSEL is low-level, the drive unit 53switches the drive signal for touch VcomAC to the drive signal fordisplay VcomDC to be output as the drive signal Vcom. Thereafter, theoperation of the display device 1 with a touch detecting function willbe repeated.

As described above, in the display device 1 with a touch detectingfunction according to the third embodiment, the wiring for display LDCfor supplying the drive voltage for display VcomDC is arranged inparallel with the wiring for touch VcomAC for supplying a constantvoltage higher than the drive voltage for display VcomDC. Accordingly,the voltage can be supplied to the drive electrode COML by effectivelyusing the picture frame area Gd.

Fourth Embodiment

The following describes a display device 1 with a touch detectingfunction according to a fourth embodiment. Components similar to thoseof the first embodiment are denoted by the same reference numerals, andan overlapping explanation thereof will be omitted. FIG. 31 is a blockdiagram illustrating the drive signal generation unit of the driveelectrode driver according to the fourth embodiment. FIG. 32 is a blockdiagram illustrating the drive electrode driver according to the fourthembodiment. FIG. 33 is an explanatory diagram illustrating an example ofthe timing waveform of the display device 1 with a touch detectingfunction according to the fourth embodiment.

FIG. 31 is a block diagram illustrating the drive signal generation unitof the drive electrode driver according to the fourth embodiment. Thedrive signal generation unit 14Q includes the high-level voltagegeneration unit 61, the low-level voltage generation unit 62, thebuffers 63 and 64, and the switching circuit 65.

The high-level voltage generation unit 61 generates a high-level voltageof the drive signal VcomAC. The low-level voltage generation unit 62generates a direct current voltage of the drive voltage for displayVcomDC. The voltage generated by the low-level voltage generation unit62 is also used as a low-level voltage of the drive signal VcomAC. Thebuffer 63 outputs the voltage supplied from the high-level voltagegeneration unit 61 while performing impedance conversion thereon, andsupplies the voltage to the switching circuit 65. The buffer 64 outputsthe voltage supplied from the low-level voltage generation unit 62 whileperforming impedance conversion thereon, and supplies the voltage to theswitching circuit 65. The switching circuit 65 alternately repeats acase in which a drive control signal EXVCOM is high-level and a case inwhich the drive control signal EXVCOM is low-level based on the drivecontrol signal EXVCOM, and generates the drive signal VcomAC. Theswitching circuit 65 outputs the voltage supplied from the buffer 63when the drive control signal EXVCOM is high-level, and outputs thevoltage supplied from the buffer 64 when the drive control signal EXVCOMis low-level. The switching circuit 65 outputs the voltage supplied fromthe buffer 64 as the direct current voltage of the drive voltage fordisplay VcomDC when the drive control signal EXVCOM is low-level, basedon the drive control signal EXVCOM. The buffers 63 and 64 include, forexample, a voltage follower. The voltage from the switching circuit 65is output to an output terminal 65E.

FIG. 32 is a block diagram illustrating the drive electrode driveraccording to the fourth embodiment. The drive electrode scanning units14A and 14B include the scanning control unit 51, the touch detectionscanning unit 52, and the drive unit 530. The drive unit 530 includesthe drive units 53(k) to 53(k+3) the number of which is the same as thatof the drive electrode blocks B. The scanning control unit 51 is mountedon the COG 19. The touch detection scanning unit 52 and the drive unit530 are arranged in the picture frame at the periphery of the displayarea Ad. Hereinafter, to indicate any one of the drive units 53(k) to53(k+3), a “drive unit 53” is simply referred to.

The scanning control unit 51 supplies the scanning start signal SDST tothe touch detection scanning unit 52 based on the control signalsupplied from the control unit 11. Any one of the drive voltage fordisplay VcomDC and the drive signal VcomAC output from the drive signalgeneration unit 14Q via the output terminal 65E is supplied to wiringLCC. The scanning control unit 51 supplies the drive electrode selectionsignal VCOMSEL to the drive unit 530. The drive electrode selectionsignal VCOMSEL is a signal for identifying a period in which the drivesignal VcomAC is supplied from the drive signal generation unit 14Q tothe drive electrode COML via the wiring LCC.

The touch detection scanning unit 52 includes the shift registers 52SR1and 52SR2, and generates the transfer circuit outputs SRout(k),SRout(k+1), SRout(k+2), SRout(k+3) . . . for selecting the driveelectrode COML to which the drive signal VcomAC is applied.Specifically, the touch detection scanning unit 52 causes the scanningstart signal SDST as a trigger supplied from the scanning control unit51 to the shift register 52SR1 to be synchronized with the driveelectrode selection signal VCOMSEL so as to be sequentially transferredto the shift register 52SR2 next to the shift register 52SR1 and besequentially selected. The shift register 52SR2 generates the transfercircuit outputs TRN(k), TRN(k+1), TRN(k+2), TRN(k+3) . . . as idletransfer signals, and transfers the outputs to the next shift register52SR1.

The shift register 52SR1 selected in synchronization with the driveelectrode selection signal VCOMSEL sends out the transfer circuitoutputs SRout(k), SRout(k+1), SRout(k+2), SRout(k+3) . . . to eachamplification circuit 54 of the drive unit 530. In the touch detectionscanning unit 52, for example, when the selected shift register 52SRsupplies a high-level signal as the k+2-th transfer circuit outputSRout(k+2) to the k+2-th drive unit 53(k+2), the drive unit 53(k+2)applies the drive signal VcomAC to a plurality of drive electrodes COMLbelonging to the k+2-th drive electrode block B(k+2).

As illustrated in FIG. 33, the display device 1 with a touch detectingfunction according to the fourth embodiment separately performs a touchdetection operation (touch detection operation period Pt) and a displayoperation (display period Pd), and supplies the drive signal Vcom (thedrive voltage for display VcomDC and the drive signal VcomAC) to thedrive electrode COML in a time-division manner.

The drive electrode COML functions as the drive electrode of the liquidcrystal display unit 20 and also as the drive electrode of the touchdetection unit 30, so that the drive signals Vcom may influence eachother. Accordingly, the drive signal Vcom is applied to the driveelectrode COML separately in the display operation period Pd forperforming a display operation and the touch detection operation periodPt for performing a touch detection operation. The drive electrodedriver 14 applies the drive signal Vcom as the drive voltage for displayin the display operation period Pd for performing a display operation.The drive electrode driver 14 then applies the drive signal Vcom as thetouch drive signal in the touch detection operation period Pt forperforming a touch detection operation. In this way, in the displaydevice 1 with a touch detecting function, the drive voltage for displayVcomDC and the drive signal VcomAC are supplied to the same wiring LCCin different time periods. The waveform of the drive signal VcomAC is awaveform synchronized with a rectangular wave of the drive controlsignal EXVCOM.

As illustrated in FIG. 33, in the touch detection operation, one ofswitches SWx of the selection drive electrode block STX is turned on(closing operation) and the rectangular wave of the drive signal VcomACis applied thereto to perform scanning for touch detection. In the touchdetection operation, all of the selection switches SWx of thenon-selection drive electrode block NTX are turned off (openingoperation), and the electric potential of the non-selection driveelectrode block NTX is caused to be in a floating state, that is, theelectric potential is not fixed. In this case, it is preferable toadjust a gate potential of the selection switch SWx of the non-selectiondrive electrode block NTX so that all of the selection switches SWx ofthe non-selection drive electrode block NTX are fully turned off.

The display device 1 with a touch detecting function turns on all of theswitches SW1 to SW4 in the display period Pd, and applies the drivevoltage for display VcomDC to the drive electrode COML. As describedabove, in the display device 1 with a touch detecting function accordingto the fourth embodiment, the control device supplies the drive voltagefor display VcomDC and the drive signal for touch VcomAC to the samewiring for touch LCC in different time periods. Due to this, the displaydevice 1 with a touch detecting function according to the fourthembodiment can further narrow the picture frame area Gd. Accordingly,the entire circuits in the picture frame area can be brought near thedisplay area Ad, and quality can be improved by preventing infiltrationof water or cracking. The picture frame area Gd according to the firstembodiment can also reduce the resistance of the wiring for touch LAC.As a result, the waveform distortion of the drive signal for touchVcomAC is improved and the accuracy in touch detection can be enhanced.The circuit for generating the control signals SDCK1 and SDCK2 becomesunnecessary and the size of the circuit of the COG 19 is reduced, sothat the IC can be downsized. The picture frame area Gd according to thefourth embodiment can also reduce the resistance of the wiring for touchLAC and narrow the picture frame area Gd.

Fifth Embodiment

The following describes a display device 1 with a touch detectingfunction according to a fifth embodiment. Components similar to those ofthe first to the fourth embodiments are denoted by the same referencenumerals, and an overlapping explanation thereof will be omitted. FIG.34 is a block diagram illustrating the drive signal generation unit ofthe drive electrode driver according to a fifth embodiment. FIG. 35 isan explanatory diagram illustrating an example of the timing waveform ofthe display device 1 with a touch detecting function according to thefifth embodiment.

As illustrated in FIG. 34, the touch detection scanning unit 52 includesthe shift register 52SR1 for a drive electrode and the shift register52SR2 for a drive electrode serving as the transfer circuits. The shiftregister 52SR1 for a drive electrode generates the transfer circuitoutputs SRout(k), SRout(k+1), SRout(k+2), SRout(k+3) . . . for selectingthe drive electrode COML to which the drive signal for touch VcomAC isapplied. Specifically, the touch detection scanning unit 52 causes thescanning start signal SDST as a trigger supplied from the scanningcontrol unit 51 to the shift register 52SR1 to be synchronized with thecontrol signal SDCK1 so as to be sequentially transferred for eachtransfer stage of the shift register 52SR and be sequentially selected.The selected shift register 52SR1 sends out the transfer circuit outputsSRout(k), SRout(k+1), SRout(k+2), SRout(k+3) . . . to each logic circuit55 of the drive unit 530. The logic circuit 55 generates and outputs alogical product (AND) of the transfer circuit output SRout supplied fromthe touch detection scanning unit 52 and the drive electrode selectionsignal VCOMSEL supplied from the scanning control unit 51. That is, thetransfer circuit output SRout of the shift register 52SR1 can controlthe operation of the selection switch SW1 (SW2, SW3, SW4) via the outputfrom the logic circuit 55. The logic circuit 55 is coupled to theamplification circuit 54 having a buffer function for amplifying theoutput of the logic circuit 55 to the amplitude level. In the touchdetection scanning unit 52, when the selected shift register 52SRsupplies, for example, a high-level signal to the k+2-th drive unit53(k+2) as the k+2-th transfer circuit output SRout(k+2), the drive unit53(k+2) applies the drive signal VcomAC to the drive electrodes COMLbelonging to the k+2-th drive electrode block B(k+2).

As illustrated in FIG. 35, when the scanning start signal SDST is input,the shift register 52SR1 outputs the transfer circuit output SRout1 ashigh-level in synchronization with the control signal SDCK1 using thescanning start signal SDST as a trigger. When the drive electrodeselection signal VCOMSEL is high-level, the logic circuit 55 outputs thedrive signal for touch VcomAC as the waveform Tx1 of the drive signalVcom. When the shift register 52SR1 outputs the transfer circuit outputSRout1 as low-level, the shift register 52SR2 receives the transfercircuit output SRout1 and performs idle transfer to output the transfercircuit output TRN1. When the drive electrode selection signal VCOMSELis low-level, the drive unit 53 switches the drive signal for touchVcomAC to the drive signal for display VcomDC to be output as the drivesignal Vcom.

The display device 1 with a touch detecting function according to thefifth embodiment includes the shift register 52SR1 serving as the firsttransfer circuit and the shift register 52SR2 serving as the secondtransfer circuit. The shift register 52SR1 serving as the first transfercircuit is a transfer circuit that controls the selection switch SW1(SW2, SW3, SW4) via the logic circuit 55. The shift register 52SR2serving as the second transfer circuit supplies the transfer circuitoutput to the shift register 52SR1. The display device 1 with a touchdetecting function according to the fifth embodiment does not includethe control signal line LSDCK2 for transmitting the control signalSDCK2, so that the width Wtx can be reduced by about half of the widthΔWCK illustrated in FIG. 20. Due to this, the picture frame area Gdaccording to the fifth embodiment can be narrowed.

The embodiment has been described above by exemplifying some embodimentsand modifications. However, the embodiment is not limited thereto andvarious modifications can be made.

In the display device 1 with a touch detecting function according to theabove-described embodiments and modifications, the display unit 10 witha touch detecting function can be made by integrating the touchdetection unit 30 with the liquid crystal display unit 20 using liquidcrystals of various modes such as the FFS mode and the IPS mode. FIG. 36is a sectional view of a schematic sectional structure of the displayunit with a touch detecting function according to a modification.Instead of this, a display unit 10 with a touch detecting functionaccording to the modification illustrated in FIG. 36 may be formed byintegrating liquid crystals of various types of modes, such as a twistednematic (TN) mode, a vertical alignment (VA) mode, and an electricallycontrolled birefringence (ECB) mode, and a touch detecting unit.

As illustrated in FIG. 36, when the counter substrate 3 includes thedrive electrode COML, the wiring for display LDC, the wiring for touchLAC, or the wiring LCC may be provided to the counter substrate 3. Thewiring LCC is arranged in the picture frame area Gd positioned on theoutside of the display area Ad in the direction perpendicular to the TFTsubstrate 21.

In the above embodiments, the liquid crystal display unit 20 isintegrated with the capacitive touch detection unit 30. However, theembodiment is not limited thereto. Alternatively, for example, theliquid crystal display unit 20 and the capacitive touch detection unit30 are mounted on a device. In such a device on which the liquid crystaldisplay unit 20 and the capacitive touch detection unit 30 are mounted,the second drive electrode COML is provided on the surface of the glasssubstrate 31 in the counter substrate 3 in addition to the driveelectrode COML of the pixel substrate 2 illustrated in FIG. 8 serving asthe first drive electrode COML, and the first drive electrode COML iselectrically coupled to the second drive electrode COML. Also in thiscase, due to the configuration as described above, touch detection canbe performed while suppressing influence of external noise or noisetransmitted from the liquid crystal display unit (corresponding to theinternal noise in the embodiments described above).

2. APPLICATION EXAMPLES

The following describes application examples of the displaying device 1with a touch detecting function explained in the embodiments and themodifications with reference to FIG. 37 to FIG. 44. FIG. 37 to FIG. 44are schematics of examples of an electronic apparatus to which thedisplay device with a touch detecting function according to the presentembodiments is applied. The display device 1 with a touch detectingfunction according to the first, the second, the third, the fourthembodiments or the modifications thereof is applicable to electronicapparatuses of all fields, such as television apparatuses, digitalcameras, notebook personal computers, portable electronic apparatusesincluding mobile phones, and video cameras. In other words, the displaydevice 1 with a touch detecting function according to the first, thesecond, the third, the fourth embodiments and the modifications thereofare applicable to electronic apparatuses of all fields that displayvideo signals received from the outside or video signals generatedinside thereof as an image or video.

FIRST APPLICATION EXAMPLE

An electronic apparatus illustrated in FIG. 37 is a television apparatusto which the display device 1 with a touch detecting function accordingto the first, the second, the third, the fourth embodiments or themodifications thereof is applied. The television apparatus has a videodisplay screen 510 including a front panel 511 and a filter glass 512,for example. The video display screen 510 corresponds to the displaydevice with a touch detecting function according to the first, thesecond, the third, the forth embodiments or the modifications.

SECOND APPLICATION EXAMPLE

An electronic apparatus illustrated in FIG. 38 and FIG. 39 is a digitalcamera to which the display device 1 with a touch detecting functionaccording to the first, the second, the third, the fourth embodiments orthe modifications thereof is applied. The digital camera includes alight emitting unit 521 for flash, a display unit 522, a menu switch523, and a shutter button 524, for example. The display unit 522corresponds to the display device with a touch detecting functionaccording to the first, the second, the third, the forth embodiments orthe modifications.

THIRD APPLICATION EXAMPLE

An electronic apparatus illustrated in FIG. 40 is a video camera towhich the display device 1 with a touch detecting function according tothe first, the second, the third, the fourth embodiments or themodifications thereof is applied. The video camera includes a main body531, a lens 532 provided to the front side surface of the main body 531and used for photographing a subject, a start/stop switch 533 used inphotographing, and a display unit 534, for example. The display unit 534corresponds to the display device with a touch detecting functionaccording to the first, the second, the third, the forth embodiments orthe modifications.

FOURTH APPLICATION EXAMPLE

An electronic apparatus illustrated in FIG. 41 is a notebook personalcomputer to which the display device 1 with a touch detecting functionaccording to the first, the second, the third, the fourth embodiments orthe modifications thereof is applied. The notebook personal computerincludes a main body 541, a keyboard 542 used for input of characters,and a display unit 543 that displays an image, for example. The displayunit 543 corresponds to the display device with a touch detectingfunction according to the first, the second, the third embodiments orthe modifications.

FIFTH APPLICATION EXAMPLE

An electronic apparatus illustrated in FIG. 42 and FIG. 43 is a mobilephone to which the display device 1 with a touch detecting functionaccording to the first, the second, the third, the fourth embodiments orthe modifications thereof is applied. FIG. 42 is a front view of themobile phone in an opened state. FIG. 43 is a front view of the mobilephone in a folded state. The mobile phone includes an upper housing 551and a lower housing 552 connected by a connection (a hinge) 553, forexample. The mobile phone includes a display 554, a sub-display 555, apicture light 556, and a camera 557. The display 554 is provided withthe display device 1 with a touch detecting function.

SIXTH APPLICATION EXAMPLE

An electronic apparatus illustrated in FIG. 44 operates as a mobilecomputer, a multifunctional mobile phone, a mobile computer capable ofmaking a voice call, or a mobile computer capable of performingcommunications. The electronic apparatus is a portable informationterminal, which may be called a smartphone or a tablet terminal. Theportable information terminal includes a display unit 562 on the surfaceof a housing 561, for example. The display unit 562 corresponds to thedisplay device 1 with a touch detecting function according to the first,the second, the third, the fourth embodiments or the modificationsthereof.

Within the scope of the present invention, various changes andmodifications can be easily conceivable by those skilled in the art, andthe changes and modifications are considered to be encompassed in thescope of the invention. For example, even when other components areadded or eliminated, design is changed, processes are added or omitted,or conditions are changed with respect to the embodiments describedabove, the embodiments are encompassed in the scope of the inventionwithout deviating from the gist of the invention. Other working effectsobtained from the aspects described in the embodiments that is clearfrom the description of the specification or that can be appropriatelyconceivable by those skilled in the art are considered to be naturallyobtained from the present invention.

3. ASPECTS OF PRESENT DISCLOSURE

The present disclosure includes the following aspects.

(1) A display device with a touch detecting function including:

a plurality of pixel electrodes arranged in a display area;

a plurality of drive electrodes arranged opposed to the pixelelectrodes;

a control device that applies a drive voltage for display between theplurality of pixel electrodes and the plurality of drive electrodes;

a touch detection electrode opposed to the plurality of driveelectrodes;

wiring for touch that is arranged in a peripheral area positionedoutside of the display area and supplies a drive signal for touch to theplurality of drive electrodes; and

a selection switch that selects one of the plurality of drive electrodesto be coupled to the wiring for touch,

wherein the control device includes a drive electrode scanning unitselecting one of the plurality of drive electrodes, the drive electrodescanning unit includes a plurality of transfer circuits for supplyingthe drive signal for touch in the peripheral area, and part of thetransfer circuits is a transfer circuit that controls the selectionswitch.

(2) The display device with a touch detecting function according to (1),wherein the transfer circuits are arranged side by side in a directionin which the wiring for touch extends.

(3) The display device with a touch detecting function according to (1),wherein the transfer circuits include a first transfer circuit thatcontrols the selection switch and a second transfer circuit thatsupplies a transfer circuit output to the first transfer circuit.

(4) The display device with a touch detecting function according to (2),wherein the transfer circuits include a first transfer circuit thatcontrols the selection switch and a second transfer circuit thatsupplies a transfer circuit output to the first transfer circuit.

(5) The display device with a touch detecting function according to (1),further including a transfer circuit for display that scans the pixelelectrodes,

wherein the transfer circuit for display is arranged in the peripheralarea, and

the number of the transfer circuits provided for one drive electrode issmaller than the number of transfer circuits for display for scanningthe pixel electrodes overlapping with the drive electrode.

(6) The display device with a touch detecting function according to (1),further including wiring for display that supplies the drive voltage fordisplay,

wherein the wiring for display is arranged in parallel with the wiringfor touch that supplies the drive signal for touch.

(7) The display device with a touch detecting function according to (1),further including wiring for display that supplies the drive voltage fordisplay,

-   -   wherein the wiring for display is arranged in parallel with the        wiring for touch that supplies a constant voltage higher than        the drive voltage for display.

(8) The display device with a touch detecting function according to (1),wherein the control device supplies the drive voltage for display andthe drive signal for touch to the same wiring for touch in differenttime periods.

(9) The display device with a touch detecting function according to (1),further including a plurality of transfer circuits for supplying a drivesignal for touch to the drive electrode, wherein the transfer circuitsare arranged in the peripheral area for one drive electrode, and

among the transfer circuits, a second transfer circuit different from afirst transfer circuit that controls the selection switch outputs atransfer circuit output of idle transfer.

(10) The display device with a touch detecting function according to(1), wherein a drive electrode to which the drive signal for touch issupplied is selected corresponding to a change in a level of a driveelectrode selection signal that identifies an operation period for touchdetection.

(11) The display device with a touch detecting function according to(1), further including a control signal line that transmits a driveelectrode selection signal identifying an operation period for touchdetection,

wherein the control signal line is arranged in the peripheral area andis coupled to the transfer circuits.

(12) An electronic apparatus including:

a display device with a touch detecting function,

-   -   the display device with a touch detecting function including:    -   a plurality of pixel electrodes arranged in a display area;    -   a plurality of drive electrodes arranged opposed to the pixel        electrodes;    -   a control device that applies a drive voltage for display        between the plurality of pixel electrodes and the plurality of        drive electrodes based on an image signal;    -   a touch detection electrode opposed to the drive electrode;    -   a touch detection unit coupled to the touch detection electrode;    -   wiring for touch that is arranged in a picture frame area        positioned outside of the display area and supplies a drive        signal for touch to the plurality of drive electrodes; and    -   a selection switch that selects one of the plurality of drive        electrodes to be coupled to the wiring for touch,

wherein the control device includes a drive electrode scanning unit thatselects one of the plurality of drive electrodes to which the drivesignal for touch is supplied,

the drive electrode scanning unit includes a plurality of transfercircuits for supplying the drive signal for touch to the one of theplurality of drive electrodes, and

part of the transfer circuits is a transfer circuit that controls theselection switch.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention is claimed as follows:
 1. A display device comprising: afirst drive electrode and a second drive electrode arranged in a displayarea; a touch detection electrode opposed to the first and second driveelectrodes; a first wiring that is arranged in a peripheral areapositioned outside of the display area and is configured to supply analternating-current signal; a first selection switch connected betweenthe first drive electrode and the first wiring, and a second selectionswitch connected between the second drive electrode and the firstwiring; and a drive electrode scanning unit configured to control thefirst and second selection switches, wherein the drive electrodescanning unit includes a first sift register configured to control thefirst selection switch, a second sift register configured to control thesecond selection switch, and a third shift register connected to thefirst shift register and second sift register.
 2. The display deviceaccording to claim 1, wherein the first, second, and third shiftregisters are arranged side by side in a direction in which the firstwiring extends.
 3. The display device according to claim 1, wherein anoutput of the first shift register is supplied to the third shiftregister, and an output of the third shift register is supplied to thesecond shift register.
 4. The display device according to claim 2,wherein a control signal is supplied to the first, second, and thirdshift registers.
 5. The display device according to claim 1, furthercomprising a plurality of scanning signal lines in the display area, anda transfer circuit configured to control the plurality of scanningsignal lines, wherein the transfer circuit is arranged in the peripheralarea, and the first, second, and third shift registers are arrangedbetween the transfer circuit and the display area.
 6. The display deviceaccording to claim 1, further comprising a control device configured tosupply a drive voltage for display and the alternating-current signal tothe first wiring in different time periods.
 7. The display deviceaccording to claim 2, wherein the first drive electrode is arranged nextto the second drive electrode.